Building an Azure architecture that’s ready for every signature
At Exclaimer, we help organizations manage email signatures at scale, so every message can carry a consistent, compliant, on-brand signature without IT teams manually updating thousands of mailboxes. This is more difficult than it may seem, especially when you're doing it for more than 80,000 customers, around 9.6 million seats, and more than 21 billion emails a year. Every signature must show up in the right place, with the right details, for the right sender, recipient, device, and business rule. Behind that are constantly changing employee records, customer-specific policies, email chains, recipient lists, regional disclaimers, and brand requirements. Because our platform sits directly in the email flow, availability is critical. And because many of our customers operate in regulated industries, they also need confidence that data stays in-region and configured signatures are applied consistently. To support that level of scale and reliability, we’ve spent the last several years evolving our architecture on Microsoft Azure. Today, Azure Kubernetes Service (AKS), Azure SQL Database, Azure Database for PostgreSQL, Azure Cosmos DB, Azure Data Explorer, and Azure Databricks help us run a global platform that’s more responsive, more resilient, and more cost-efficient. Reading the signs that our architecture needed to change In the beginning, our cloud product ran more like a multi-server, on-premises product hosted on Azure Virtual Machines (VMs). The platform was split into a smaller number of core services, and the team relied heavily on VM-based infrastructure to keep those services running. As Exclaimer grew, our architecture had to keep pace with higher volumes, more regions, and more complex customer requirements. Regional demand shifted throughout the day, but scaling infrastructure up and down still relied on scripts, pre-baked VMs, and operational coordination. That created more risk during maintenance and failover. We run parallel data centers in regional pairs so we can move traffic away from one site when needed. But when traffic moves, the receiving environment has to be ready to handle the full load. In the VM world, that meant someone or something had to remember to scale up standby resources at the right moment. At the same time, our product was becoming more service-oriented. We were moving away from a smaller set of larger services toward well over 100 microservices. Every new service created more conversations about VM sizing, images, patching, and operational overhead. It was time for a model that could scale faster, run more efficiently, and reduce the amount of infrastructure work required to ship and operate the product. Signing on to AKS for faster, more efficient scaling By moving many workloads to Linux containers on AKS, we gained a smaller footprint, faster startup times, and a more consistent way to package and deploy services. AKS also gave us a managed Kubernetes foundation for running those containers at global scale, with autoscaling capabilities that better matched our traffic patterns. With Horizontal Pod Autoscaler, services can react to load in seconds rather than minutes. With Cluster Autoscaler, we can add or remove node capacity based on what the platform actually needs. That means we can pack workloads onto nodes more efficiently, scale down during quiet periods, and scale up quickly when demand returns. The operational difference is just as important. During an incident, maintenance event, or regional failover, our teams have fewer manual steps to think about. If traffic shifts, the platform can scale with it. That takes away one more thing for engineers to worry about when they should be focused on keeping the customer experience steady. The move to containers and a more streamlined CI/CD workflow also improved our deployment cadence by making it easier to build, test, and deploy changes across the platform. In 2021, we deployed 285 changes, features, and fixes to production over the course of the entire year. Today, we deploy that many every few days. Cost has improved, too. Since 2024, when the bulk of our migration to containerized services took place, we’ve reduced our average cost per user by about 39 percent, even as the product has grown more complex and we’ve added more capabilities for customers. We achieved that through a combination of containerized architecture, AKS autoscaling, and expanded reservations across compute and storage technologies. Choosing the right database for the right kind of data We started with a strong Microsoft SQL Server foundation, and Azure SQL Database remains core to our platform today. It stores critical customer configuration data and continues to give us the reliability, replication, resizing flexibility, and regional scale we need. But not every workload belongs in the same database. Customer configuration, relational service data, key-value storage, usage events, and business intelligence (BI) all have different access patterns. That principle led us to Azure Database for PostgreSQL flexible server for one of our most important migrations. We had used Azure Table storage for a core service that needed to retrieve customer data quickly. It was cost-effective and stable for a long time, but as the product evolved, the data became more relational, and we found ourselves adding complexity in application code that a relational database could handle more naturally. Azure Database for PostgreSQL gave us that relational model with low management overhead, fast read replicas, reserved instances for predictable workloads, and a path to future scale. After the migration, average request time for a critical service dropped from 18.6 milliseconds to 1.79 milliseconds. That’s a 90 percent improvement across a service that handles around 9 billion requests each month. Azure Cosmos DB plays a different role, supporting key-value and document storage where we need scale, availability, low latency, encryption at rest, and straightforward dev/test support. Optimized for unstructured data and high-performance reads and writes, it gives us a highly scalable foundation for workloads that don't fit a traditional relational model. We use it to store customer assets for signatures and video branding, high-volume metadata for internal message-processing operations, audit events that help customers track account changes, and tokens used to collect data from third-party systems on behalf of customers. It also gives us a clean way to keep data and services aligned. Azure Data Explorer solved another scaling challenge: usage and billing data. We need to be able to audit the number of messages we process for our customers so we can bill accurately, and at more than 20 billion emails a year, our previous SQL-based usage pipeline became difficult to manage. With Azure Data Explorer, we can ingest massive volumes of event data at low storage cost, connect to Azure Event Hubs, and avoid maintaining custom plumbing. That move reduced the cost of the system by around 70 percent. Azure Databricks rounds out the picture as our BI and data platform, giving our teams a shared foundation for transformations, analysis, and reporting across product and business data. Keeping every region ready for business Our customers are everywhere, so our platform has to be, too. Exclaimer runs in seven distinct geographic locations: Australia, Canada, Europe, Germany, the United Arab Emirates, the United Kingdom, and the United States. That global footprint helps us meet customer expectations around availability and data residency. Many organizations want their data to stay in-region, and Azure gives us the coverage we need to support that. Availability is especially important because our platform is part of a live communication flow. When someone sends an email, they expect it to keep moving. Our Azure architecture helps us support that expectation across the stack. AKS lets compute scale with regional demand. Azure SQL and Azure Database for PostgreSQL support critical relational workloads. Azure Cosmos DB gives us scalable, low-latency storage for document and key-value patterns. Azure Data Explorer handles very high-volume usage ingestion without the complexity of our former custom pipeline. Across the board, these managed Azure services reduce the amount of operational work our engineers have to carry. We can spend less time maintaining the basics and more time tuning performance, improving stability, and building the capabilities our customers need next. Building for the future on a stronger foundation The biggest sign that our architecture is working may be how little we have to reinvent when we build something new. As we develop upcoming product capabilities, we already have many of the foundational pieces in place: AKS for compute, Azure Cosmos DB for state, and Azure Service Bus for messaging. We also have Azure SQL for core data, Azure Database for PostgreSQL where relational service data needs room to scale, Azure Data Explorer for high-volume event analysis, and Azure Databricks for BI tooling. Together, these services make our platform faster, more efficient, and more resilient. Email signatures may look simple on the surface. Behind every one, there’s a set of decisions about performance, scale, data, availability, and trust. With Azure, we’ve built an architecture that helps us keep every signature moving, wherever our customers do business. About the authors Phil Vetter started in engineering at Exclaimer as a developer at the start of 2013, and now sits at the helm as VP of Engineering. Lee Jones started at Exclaimer in 2013 in the IT department, and now serves as Director of Platform Engineering, managing the infrastructure and resilience of Exclaimer Cloud.Azure Databricks at Databricks Data + AI Summit 2026: updates and new announcements
Databricks Data + AI Summit brings together the global data and AI community in San Francisco to share product news, technical breakthroughs, and customer stories. This year, as usual, we have a lot of Azure Databricks announcements, a strong presence across the event, and a continued focus on helping customers put their data to work across analytics, AI, and enable business productivity. Find us at Data and AI Summit As a Legend Sponsor and Databricks’ long-standing strategic partner, Microsoft is joining Databricks Data + AI Summit during the keynote, multiple breakout sessions, and at the Expo booth. We're also engaging with customers 1:1 to hear from you. Satya Nadella will join Ali Ghodsi, CEO Databricks, in a pre-recorded keynote conversation on the importance of data in AI implementation and the deep integrations we co-engineer. We encourage you to visit us at the Microsoft Booth (Booth # 103) on the Expo floor to chat with the Azure Databricks team, see demos, and learn more about the recent announcements. Azure Databricks Breakout Sessions Unlocking the Microsoft Data & AI Ecosystem with Azure Databricks: From Insight to Impact Wednesday, June 17 | 1:50 PM – 2:30 PM PDT | Speaker: Anavi Nahar, Head of Product, Azure Data Lake Storage & Azure Databricks, Microsoft In today’s data-driven landscape, organizations need more than analytics—they need a unified platform that turns raw data into actionable intelligence across the Microsoft ecosystem. This session explores how Azure Databricks serves as the backbone of modern data architecture, integrating with core Microsoft cloud services and platforms to accelerate innovation. Learn how to use Azure Databricks for scalable data engineering, advanced analytics, and AI-driven solutions while enabling real-time collaboration and governance. Through practical examples and architectural patterns, we’ll show how to eliminate data silos, optimize performance, and empower teams to deliver insights faster. Zero-Copy Federated Energy Analytics: ADME + Databricks in Action Wednesday, June 17 | 12:40 PM - 1:20 PM PDT | Speaker: Andy Corran, Principal Product Manager, Azure Databricks, Microsoft Oil and gas companies have standardized on Azure Data Manager for Energy (ADME) as their subsurface system of record, but running analytics and AI on that data has meant copying massive datasets into downstream platforms, breaking governance and slowing every workflow that follows. In this jointly developed Microsoft and Databricks session, we introduce a new zero‑copy, federated path that brings Databricks compute directly to data, with native governance and serverless scale. We walk through the architecture, show the solution in action against live ADME, and share how operators across the industry are accelerating subsurface analytics while keeping ADME as the single source of truth. Unity Catalog External Locations: Extending Governance to OneLake and Beyond Wednesday, Jun 17 | 5:20 PM - 5:40 PM PDT | Speaker: Ljubica Vujovic Boskovic, Senior Product Manager, Databricks In this session, we'll show how External Locations provide a consistent, extensible pattern for connecting Databricks to any storage platform — and walk through what it takes to create External Location for Microsoft OneLake. You'll see the architecture, the setup end-to-end, and a demo reading and writing UC-governed assets directly into OneLake storage without needing to setup any ETL pipelines. Latest announcements We recently announced new ways to build AI apps and agents with Azure Databricks, Copilot Studio, and GitHub Copilot, including authoring Copilot Studio agents that reason over an entire Azure Databricks workspace through one MCP connection. At Microsoft Build, PepsiCo also shared its blueprint for agentic AI, illustrating how Azure Databricks can provide the data foundation for agentic apps. This week’s announcements make it easier to use Azure Databricks with the Microsoft tools your teams rely on every day, including Microsoft Teams, M365 Copilot, Excel, SharePoint, Power BI, and OneLake: Genie for Microsoft Teams and M365 Copilot (Beta): You can tag Genie in a Teams thread and get a context-aware answer from your Azure Databricks lakehouse without leaving the conversation. Responses are governed by Unity Catalog, so each answer is scoped to what the user is permitted to see. It’s part of the broader Genie One experience for report generation, reusable agents, low-code apps, and natural-language pipeline design. See it in action in the Databricks + Microsoft co-authored training in AI Skills Navigator Genie in Copilot Cowork (Beta): Available today, Databricks Genie works seamlessly with M365 Copilot Cowork. This integration will allow teams to anchor Cowork’s tasks with the Genie Ontology, bringing trusted data intelligence straight into their workflows Azure Databricks Excel Add-in (Public Preview): This brings governed lakehouse data into Excel without SQL or per-user ODBC setup. Unity Catalog metric views let business logic be defined once and stay consistent across tools, and the add-in supports write-back, so permitted users can push updates from Excel into Databricks. Learn how to set it up. SharePoint Connector (Beta) via Lakeflow Connect. A fully managed connector for point-and-click ingestion pipelines that bring SharePoint content — structured sheets and unstructured PDFs, Word docs, and PowerPoints — into Delta tables, keeping downstream analytics, Genie spaces, and Excel workbooks supplied with current data. Read the documentation here. Azure Databricks OneLake Catalog Federation (Generally Available): The ability to query OneLake data directly from Azure Databricks without pipelines, duplication, or data movement is generally available. This announcement coupled with the Azure Databricks Mirrored Catalog item enable bidirectional READ from Azure Databricks and OneLake. Learn more here Storing Unity Catalog Managed Tables in OneLake (Beta): You can now customers can use OneLake as a storage location option for Unity Catalog tables in addition to Azure Data Lake Storage (ADLS). Read more on how to do this here. CustomerLake: a customer data platform inside the lakehouse Introducing CustomerLake, a Customer Data Platform (CDP) built directly within the lakehouse rather than as a separate application. CustomerLake is now available in Azure Databricks. Two kinds of agents do much of the work: Profile Agents help assemble business-ready Customer 360 profiles from fragmented sources, reducing the manual effort of stitching customer data together. Campaign Agents give marketing teams a workspace to segment audiences, recommend next-best actions, activate across channels, and continuously optimize personalized experiences. Because CustomerLake runs inside your governed storage boundary, customer data, AI models, and governance stay together — avoiding much of the data movement and duplication that come with connecting separate marketing tools. For Azure customers, that means building customer engagement on the same governed lakehouse foundation they already use for analytics and AI, rather than maintaining a parallel stack. “What excites us most about the CustomerLake and the new CDP capability is the ability to bring customer data together in a way that is actionable, timely, and scalable. By creating a more complete view of each customer, we can better understand behaviors, preferences, and needs across channels, which will help us deliver more personalized experiences and more relevant offers. Ultimately, we see this as a powerful step toward stronger engagement, deeper loyalty, and better outcomes for both our business and our customers.” Jay Malepati Global Director of Data Science, Circle K All of these announcements benefit from built in Governance with Azure Databricks Unity Catalog. By connecting governed lakehouse data to the Microsoft tools your teams already use — Teams, M365 Copilot, Excel, SharePoint, OneLake, and Power BI — these updates make it easier to put trusted AI to work on Azure. To learn more, explore the Azure Databricks documentation and try these capabilities in your own workspace.What to Do When You Hit Capacity in Azure Databricks: Engage, Mitigate, Plan!
Microsoft's Cloud Architects: Paul Singh PaulSingh, Eduardo Dos Santos eduardomdossantos, Chris Walk cwalk, Peter Lo PeterLo, Tim Orentlikher tim_orentlikher, Ajmal Hossain ajmalhossain, Chris Haynes Chris_Haynes, and Rafia Aqil Rafia_Aqil Start Here: Engage Microsoft Capacity constraints in Azure Databricks are not an Azure Databricks product issue. Azure Databricks does not own or reserve compute, it dynamically provisions VMs from Azure when clusters are created or scaled. This means cluster creation, autoscaling, or job execution can stall when the underlying VM SKUs are constrained at the regional level. The fastest path to resolution is a structured conversation with your Microsoft account team, who can engage the Azure capacity intake process on your behalf. Create a Quota Support Ticket via Microsoft Support and bring the following to your account team with your Support Ticket Number. Each field maps directly to what capacity intake teams will ask for: missing fields slow the request. What to Prepare Before You Reach Out Your Account Team Field What Capacity Intake Needs Example Subscription IDs The exact Azure subscriptions that will host the workspaces and clusters 7ebee83d-7923-426c-8449-59fd4dff25ab Region(s) Primary region, plus any acceptable alternates East US 2 VM family / SKU Specific series and version requested Eadsv5, ESv4, DSv4, DSv2 Core count / new limit Total vCPU or core count per SKU 10,000 cores for Eadsv5 Workload characteristic CPU-bound vs. memory/shuffle-heavy vs. IO-heavy; batch vs. streaming vs. SQL “Memory-intensive ETL with large joins and shuffles” Scale and timing When you need it, ramp profile, peak vs. steady state “Need by month-end; ramp from 2,000 to 9,650 cores over Q3” Business context Business use case “Migration off AWS” What “Capacity” Really Means: A Layered Mental Model Before diving into fixes, it is important to understand what is actually happening behind the scenes. Capacity constraints can occur at three distinct layers, and solving them requires addressing each one. Layer 1: Azure Infrastructure This is the layer most teams underestimate. Capacity here is governed by: VM SKU availability in the region. D-series and E-series: the two most common Databricks worker families: have repeatedly hit capacity constraints across multiple Azure regions, causing cluster creation failures, autoscale stalls, and provisioning delays. Regional supply constraints, which are dynamic and shared across all Azure tenants. vCPU quotas and limits per subscription, which are separate from regional supply. Quota is your subscription’s limit to deploy resources (like a credit card limit); regional capacity is the underlying infrastructure available. Both must be sufficient. Layer 2: Azure Databricks Platform The Azure Databricks control plane has its own published ceilings that your architecture must proactively respect. Key limits from the official Azure Databricks resource limits documentation: Resource Limit Scope Jobs created per hour 10,000 Workspace Tasks running simultaneously 2,000 Workspace (Run Job and For Each parent tasks excluded) Parent tasks running simultaneously (Run Job / For Each) 750 Workspace SQL warehouses 1,000 Workspace Attached notebooks or execution contexts 145 Cluster Virtual machines 25,000 Per subscription per region Note: For limits marked as non-fixed in the official documentation, you can request an increase through your Azure Databricks account team. Reference: https://learn.microsoft.com/en-us/azure/databricks/resources/limits Layer 3: Workload (Spark Execution) Even when both lower layers cooperate, Spark’s own execution model can produce capacity-like symptoms: Parallelism and task distribution, which dictate how many cores a job can usefully consume. Memory pressure from joins, shuffles, and skewed keys. IO demand and caching behavior, including Delta cache effectiveness and Spark cache misuse. Understanding these layers is critical. Retries sometimes succeed because capacity is dynamic: as other workloads complete, nodes are released back to Azure and briefly become available. Recognizing When You’ve Hit Capacity Capacity issues rarely present as a single clean error. Instead, they appear as inconsistent behaviors: Clusters stuck in Pending state Autoscaling fails or never reaches the desired size Jobs intermittently fail to start Retry attempts sometimes succeed These inconsistencies occur because capacity is shared across Azure tenants and fluctuates throughout the day. Running workloads outside peak business hours in the impacted region’s time zone is one of the most effective short-term mitigations. Immediate Actions: How to Unblock Your Workloads When you are actively hitting capacity constraints, speed matters. Please reach out to your Microsoft Account team and try these mitigations that are ordered from quickest to most involved. Retry and Run During Off-Peak Hours Capacity availability changes throughout the day as workloads complete and release VMs. Running outside peak business hours for the impacted region significantly improves success rates. Switch VM SKU or Family If a specific VM SKU is constrained, switching to another can immediately unblock provisioning. Move within the same family (for example, DSv4 → DSv5) Or switch families entirely (for example, D-series → F-series or L-series) This is one of the most effective but often underused approaches. Also, Choosing the Right VM Family Most Databricks environments default to D-series (general purpose) and E-series (memory optimized). These are also the most heavily used and most capacity-constrained VM families. Consider alternatives based on your workload: VM Family Best For When to Use Trade-off D-series General workloads Default choice Often constrained in high-demand regions E-series Memory-heavy Spark jobs Joins, shuffles, analytics High demand; higher cost F-series CPU-intensive jobs Parsing, transformations Lower memory per core L-series IO-heavy workloads Delta caching, large datasets Higher cost; large local NVMe Practical decision framework: Memory-bound workloads (joins, shuffles): Move from E-series to L-series. Similar memory per core, plus large local NVMe for Delta caching. CPU-bound workloads: Move from D-series to F-series. Higher CPU performance at lower cost. IO-heavy or cache-sensitive workloads: L-series can significantly improve performance and reduce shuffle pressure. Designing a single VM family is one of the biggest production risks in Azure Databricks environments. Implement Regional Diversity in your Databricks workload As Azure capacity constraints are region- and SKU-specific, it is important to build architectural flexibility into your Databricks deployments. For critical or large-scale workloads, consider deploying multiple Databricks workspaces across different Azure regions to reduce dependency on any single region’s capacity. This approach enables: improved resilience to regional capacity constraints greater flexibility in workload placement Important: Multi-region deployment requires deliberate architecture, including deploying separate workspaces and replicating data and configurations across regions—it is not automatic. Why Adding More Nodes Is Not Always the Answer When jobs slow down, the instinct is to scale compute. With Spark, more nodes do not always solve the problem. Common workload issues that masquerade as capacity problems: Data skew Excessive shuffle operations Inefficient partitioning Overuse of UDFs In real workloads, shuffle operations can grow significantly larger than input data, placing heavy pressure on both compute and memory that more nodes cannot relieve. Smarter optimization strategies: Reduce shuffle through repartitioning and query optimization Enable Photon for faster execution Optimize Delta tables using Z-ordering and compaction Leverage caching strategically (not just Spark cache: use the Delta/disk cache) These optimizations can reduce your dependency on scarce VM capacity altogether. What to Do When Your Capacity Is Approved Once Azure approves your capacity request, retaining it requires active steps. Because Azure capacity is dynamic and shared, approved capacity is held only while compute remains actively deployed and running. This is especially important in highly constrained regions. Microsoft recommends the following: Configure an Instance Pool For workloads that cannot yet use serverless compute, configure an Azure Databricks Instance Pool with a minimum number of idle nodes aligned to your production requirements. An instance pool pre-allocates and maintains a set of idle, ready-to-use VM instances. When a cluster is created from the pool, it draws from these warm nodes: eliminating the need to request new VMs from the regional Azure capacity pool between job runs. Key behaviors: The pool holds a minimum number of nodes continuously, keeping them warm and immediately available. Clusters attached to the pool pull from warm nodes, avoiding re-acquisition from Azure between runs. No DBU charges apply while nodes are idle in the pool. Azure VM infrastructure costs do apply for all minimum idle instances. Size the pool conservatively: aligned to production need only: to balance capacity retention against ongoing cost. Important: Instance pools hold idle nodes on a best-effort basis. Periodic platform events can recycle pool nodes, briefly causing the pool to fall below its configured minimum idle count while Azure re-acquires replacement nodes. Pools significantly improve availability and startup latency, but they do not change the fact that the underlying VMs are still requested from Azure on demand. They are not a hard reservation. Reference: https://learn.microsoft.com/en-us/azure/databricks/compute/pools Designing for Resilience: Long-Term Best Practices To avoid repeated capacity issues, your architecture needs to evolve beyond reactive mitigations. Plan for Capacity Early Understand VM quotas and limits before you need them: not after a constraint occurs. Avoid designing a single SKU. Build flexibility into cluster configurations so you can switch families without re-engineering jobs. Standardize Compute Configurations Consistent, policy-driven environments make it easier to adapt when capacity constraints occur. Use Databricks Cluster Policies to constrain cluster creation to approved, available VM families: this prevents teams from inadvertently requesting constrained SKUs. Move Toward Serverless Where Possible Serverless compute abstracts capacity management away from the customer. As the Databricks platform expands serverless support, migrating eligible workloads is the most durable long-term strategy. Azure continues to expand infrastructure capacity, but there are no guaranteed timelines for relief in constrained regions. Note: If your workload supports serverless compute, Databricks recommends using serverless compute instead of pools or classic VM-backed clusters. Serverless removes dependency on specific VM SKUs and regional capacity: scaling is managed by the platform with significantly improved availability. Reference: https://learn.microsoft.com/en-us/azure/databricks/serverless-compute. For eligible workloads: including Databricks Jobs (automated workflows), Databricks SQL Warehouses, and Delta Live Tables: serverless compute eliminates VM SKU dependency entirely. Configuration guidance is available in the Azure Databricks deployment guide, Development Section, Step 9. Multi-Region Strategy for Critical Workloads For the most critical workloads, evaluate a multi-region deployment as part of your business's continuity planning. This is a significant architectural investment: see the FAQ for the full scope: but it is the only approach that provides true regional redundancy. Coordinate this with your Microsoft account team. Reference: Azure Databricks & Microsoft Fabric Disaster Recovery: The Complete Better‑Together Strategy for Cloud Architects Final Takeaways Capacity issues are infrastructure-level constraints, not Databricks product failures VM family selection is critical: do not rely solely on D-series and E-series Workload optimization can reduce dependency on scarce resources before requesting more capacity Serverless compute is Microsoft’s preferred long-term recommendation for eligible workloads Azure On-Demand Capacity Reservations provide guaranteed capacity for mission-critical scenarios: distinct from instance pools (best-effort) and Reserved Instances (billing discount only) Architectural flexibility: multi-SKU, multi-region awareness is your best defense against future constraints FAQ Why do retries work? Capacity in Azure regions is shared across all tenants and fluctuates throughout the day as workloads complete and release VMs. A retry succeeds when capacity temporarily frees up. Retrying during off-peak hours improves success rates significantly. Why does capacity fluctuate during the day? Capacity is a function of regional supply and concurrent demand. As workloads complete, nodes are released back to Azure. Peak business hours in the impacted region’s time zone tend to be the tightest windows. Why are instance pools not a hard reservation? Pools hold a minimum number of nodes on a best-effort basis. Periodic platform events recycle pool nodes, so a pool can briefly fall below its configured minimum idle count while Azure re-acquires replacement nodes. Setting minimum idle to 0 avoids paying for idle VMs at the cost of slower acquisition time. Pools significantly improve availability and startup latency but do not guarantee capacity at the Azure infrastructure level. Why does serverless behave differently from classic clusters? Serverless compute removes customer control over individual VM SKUs. Databricks manages the underlying capacity across a shared pool. SKU-swap and pool-based mitigations do not apply. Customer-side levers reduce to retry and off-peak scheduling. The trade-off is that serverless is the simplest and most reliable option when the workload supports it. Why is changing regions a last resort? Region changes require redeployment of the Azure Databricks workspace and migration of all dependent artifacts: jobs, clusters, libraries, networking (private endpoints, VNet injection), Unity Catalog assignments, identities, and source data. The destination region must be validated for the same SKU and zonal configuration. For these reasons, region change should always be coordinated with the Microsoft account team and attempted only after preferred mitigations have been exhausted. Why does VM family selection matter so much for capacity? Different VM families have different supply curves. D-series and E-series are the most requested Databricks worker families and the ones most frequently constrained. Choosing a SKU based on whether the workload is memory/shuffle-heavy, CPU-bound, or IO-heavy improves both performance and the probability that capacity is available. The capacity team often steers customers toward newer-generation alternatives when supply differs by generation version. What does the Microsoft account team actually do? They route the request into the Azure capacity intake process, advise alternate SKUs and regions, surface zonal vs. regional considerations, and provide forward visibility into known constraints. The customer’s job is to bring a complete, accurate workload profile so the account team can advocate effectively. It is also recommended to open an Azure Support ticket. This will save time later, as the capacity planning teams would like to track issues and requests via a support ticket. Once an Azure Support ticket is opened, the ticket number should be shared to the Microsoft Account Team, at a minimum to the Customer Success Account Manager (CSAM), if one is assigned to your organization.Streaming and Batch Data Architectures with Microsoft Fabric to Azure Databricks
Author's: Oscar Alvarado oscaralvarado and Rafia Aqil Rafia_Aqil Note: This article describes a solution idea. Your cloud architect can use this guidance to help visualize the major components for a typical implementation. Use this article as a starting point to design a well-architected solution that aligns with your workload’s specific requirements. As organizations adopt Microsoft Fabric as their unified analytics platform, it has become a leading path for ingesting both streaming and batch data into Azure Databricks. This article covers integration approaches -via Microsoft Fabric- and details the five Fabric-specific paths that connect OneLake/ADLS and Databricks for end-to-end data processing. Medallion Architecture The following data flow corresponds to the architecture diagram: Data is ingested through Microsoft Fabric (via Mirroring, RTI, or Data Factory) lands data into OneLake/ADLS. With the medallion pattern, consisting of Bronze, Silver, and Gold storage layers, organizations have flexible access and extendable data processing: Bronze – Raw data entry point. Data arrives in its source format and is converted to the open, transactional Delta Lake format. Silver – Optimized for BI and data science. ETL and stream processing tasks filter, clean, transform, join, and aggregate Bronze data into curated datasets using SQL, Python, R, or Scala. Gold – Enriched data ready for analytics and reporting. Analysts use Power BI, PySpark, SQL, or Excel for insights and queries. Fabric Integration Paths Note: This architecture establishes a complete loop-back between Microsoft Fabric and Azure Databricks, enabling Gold layer tables to be seamlessly mirrored back to Microsoft Fabric for dashboarding through Azure Databricks Mirroring. The following five paths connect Microsoft Fabric to Azure Databricks: Fabric Mirroring to OneLake – A low-cost, low-latency turnkey solution that creates a replica of data from operational sources (SQL Server, Azure Cosmos DB, Oracle) in OneLake. Handles the initial load and ongoing CDC changes automatically, keeping data continuously up to date. Fabric RTI to OneLake – Fabric Real-Time Intelligence ingests streaming event data into OneLake with sub-second latency, enabling real-time analytics on live event streams. Fabric Data Factory to OneLake – Orchestrates ingestion from diverse sources not covered by Mirroring (such as Sybase or REST APIs) and lands data in OneLake, ensuring complete source coverage. OneLake to Azure Databricks – Unity Catalog connections to OneLake, secured via Managed Identities from Microsoft Entra ID, allow Databricks to query OneLake data items as a native catalog without data duplication. Fabric Data Factory to Azure Databricks (direct) – Orchestrates ingestion from diverse sources directly into Azure Data Lake Storage (ADLS), where Azure Databricks picks up the data for medallion architecture processing. Design Considerations Area Updated guidance Direct RTI-to-Databricks integration There is still no broad GA direct integration where Fabric RTI and Databricks operate as one native real-time runtime. Integration should be positioned through open protocols, Event Hubs/Kafka-style patterns, OneLake, Delta, and federation. OneLake federation in Azure Databricks OneLake federation in Azure Databricks is now the key integration story. It allows Databricks Unity Catalog to query Fabric Lakehouse and Warehouse data in OneLake without copying it. Access is read-only and depends on Fabric tenant settings, workspace permissions, and Databricks Unity Catalog setup. RTI data availability to Databricks Data ingested through Fabric RTI can be made available to Databricks by landing or exposing the data into OneLake-backed items, especially Lakehouse/Warehouse patterns. Eventhouse data can be made available in OneLake in Delta format through OneLake availability, but Databricks OneLake federation should be validated against the specific Fabric item type and access path. Existing Databricks customers Existing Databricks customers do not need to abandon Databricks. They can use Fabric RTI as the event ingestion, real-time detection, operational alerting, and business action layer, while continuing to use Databricks for engineering, ML, advanced analytics, and Unity Catalog-governed access. Activator and business action Fabric Activator is the cleanest business-user action layer. It can monitor streaming events and trigger Teams messages, email, Power Automate flows, Fabric pipelines, notebooks, Spark jobs, Dataflows, UDFs, and other downstream actions. This is a strong differentiator because it lets business users act on events without waiting for batch analytics. Operations Agents Operations Agents are in preview and should be positioned carefully. They monitor real-time data from Eventhouse or ontology sources, surface insights, recommend actions, and can connect to Activator/Power Automate action paths. They are not simply a pre-ingestion decision engine before data lands anywhere; they work from configured Fabric knowledge/data sources. Before landing in Lakehouse For decisioning before Lakehouse persistence, use Eventstream processing and Activator rules on streams. For AI-assisted operational recommendations, use Operations Agents once the relevant data is available in Eventhouse or ontology. Requirement-Specific Notes Data Ingestion Microsoft Fabric Mirroring currently supports SQL Server, Azure Cosmos DB, and Oracle as source systems. For sources not yet supported by Mirroring—such as Sybase or REST APIs—use Fabric Data Factory pipelines to ensure full coverage across all data systems. Once data is in the landing zone with the correct format, Mirroring’s CDC replication starts automatically and manages the complexity of merging changes (updates, inserts, and deletes) into Delta tables, keeping data in Fabric continuously up to date. Learn more about open mirroring Storage Format and Time Travel OneLake supports Delta tables, enabling schema evolution and time travel across all data stored in the lakehouse. Learn more about OneLake and Delta tables Security Encryption at rest: OneLake automatically encrypts all data at rest using Microsoft-managed keys, compliant with FIPS 140-2 standards. Learn more Encryption in transit: All data in transit is encrypted using TLS 1.2 or higher, securing data movement between Fabric, OneLake, and Azure Databricks. Learn more Data Governance OneLake can be registered and scanned by Microsoft Purview, enabling cataloging of stored metadata and data quality profiling. This protects sensitive information, including PHI and PII, across ingestion and analytics workflows. Learn more about Purview with Fabric Lakehouse Operations and Monitoring Use the Fabric monitor hub to track pipeline health, Spark application performance, and ingestion job status across all Fabric workloads. Learn more about the Fabric monitor hub Scenario Details This architecture applies to any organization that needs to unify streaming and batch data at scale. Common characteristics include: Multiple operational data sources (databases, SaaS applications, event streams) A requirement to process both real-time and historical data in the same platform Governance and compliance requirements for sensitive data (PHI, PII, financial records) Analytics consumers spanning BI (Power BI), data science (Databricks notebooks), and ML workloads Potential Use Cases Healthcare and life sciences – PHI/PII protection via Purview; real-time patient telemetry + batch EHR analytics Financial services – Real-time fraud detection streams + batch regulatory reporting Retail and e-commerce – Streaming clickstream analytics + batch inventory and supply chain processing Energy and utilities – IoT sensor telemetry streaming + batch consumption analytics Next Steps Get started with Microsoft Fabric Mirroring Build an ETL pipeline with Lakeflow Declarative Pipelines Configure Unity Catalog with OneLake shortcuts Monitor Fabric pipelines with the Fabric monitor hubBuilding AI apps and agents with Azure Databricks, Copilot Studio, and GitHub Copilot
A workspace-wide Genie MCP endpoint for Copilot Studio Genie is Azure Databricks’ AI agent that lets any employee chat with their data and get trusted answers instantly. Genie Spaces are curated, business‑domain workspaces for teams to find strategic insights for their targeted use cases. Until now, connecting Azure Databricks Genie to Microsoft Copilot Studio meant adding each Genie Space as a separate tool. This works and adds value for customers wanting to integrate a specific Genie Space with Copilot Studio, but the per-space MCP server added overhead when trying to connect multiple Genie spaces to one Copilot Studio agent. The workspace-wide MCP endpoint changes that. One endpoint per workspace gives a Copilot Studio agent access to every connected Genie space and Unity Catalog dataset, and the curated context inside each Genie space stays in place. Key capabilities: Natural-language access across the workspace. Copilot Studio agents can route questions across every connected Genie Space and Unity Catalog dataset without losing the curation that keeps answers accurate. Unity Catalog governance. Access controls are enforced at query time, so existing data permissions extend to every agent built in Copilot Studio. Beyond a single domain. Move from a finance agent or a supply chain agent to a workspace-aware agent that follows users wherever the data lives. Lakebase branching with GitHub Copilot agent mode Production AI agents fail on real-data edge cases that synthetic or mocked environments do not catch. But giving a developer direct production access to investigate is not a realistic option in most enterprises. Lakebase branching, now integrated with GitHub Copilot agent mode, gives you a way to debug against real data without ever connecting to the production database. Key capabilities: Copy-on-write branching. Create a full-fidelity branch of a Lakebase production database in seconds. No data is moved and no production records are altered. Native GitHub Copilot agent debugging. Point GitHub Copilot agent mode at the branch endpoint to reproduce, root-cause, and resolve data-dependent issues with AI assistance. Azure-native end-to-end workflow. The full loop runs across GitHub, Azure Databricks, and Lakebase. No third-party tools or custom infrastructure required. Compliance built in. Fixes ship through the standard Git-based deployment and compliance workflows already in place, so debug cycles compress from hours to minutes. What this unlocks for AI agent teams Together, the two capabilities cover both halves of the agent lifecycle on Azure: Author Copilot Studio agents that reason over an entire Azure Databricks workspace through one MCP connection. Debug production AI agents against real Lakebase data using GitHub Copilot agent mode, reducing production data risk. Keep Unity Catalog governance and existing compliance controls in place from authoring through deployment. Standardize the data, agent, and developer toolchain on GitHub, Azure Databricks, and Microsoft 365. Get started Both features are available in public preview on June 2, 2026, directly in Azure Databricks workspaces. Azure Databricks and Power Platform integration to set up Genie workspace-wide MCP for Copilot Studio Connect your GitHub to Azure Databricks to take advantage of Lakebase branching with GitHub Copilot agent modeHow to Secure Azure Databricks without Public Exposure using WAF + Private Endpoints
This blog outlines a Zero Trust–aligned architecture for securing Azure Databricks using Application Gateway (WAF) and Private Endpoints within a Hub-Spoke network model. Enables a true Zero Trust model, ensuring: No direct exposure of Databricks Full traffic inspection Compliance-ready secure access for both internal and external users
Secure Medallion Architecture Pattern on Azure Databricks (Part II)
Disclaimer: The views in this article are my own and do not represent Microsoft or Databricks. This article is part of a series focused on deploying a secure Medallion Architecture. The series follows a top-down approach , beginning with a high-level architectural perspective and gradually drilling down into implementation details using repeatable, code. In this part we will discuss the implementation of the pattern using GitHub Copilot If you have missed, please read first the first part of this blog series. It can be found at: Secure Medallion Architecture Pattern on Azure Databricks (Part I). I waited a while before publishing this article. Partly due to other priorities, but also because I wanted to experiment with deploying infrastructure and data pipelines using agents. At that point, I was looking to leverage agents with a spec-driven approach, and through using GitHub Copilot, I learned what skills are and how I can use them to achieve my scope. In this blog I'll share what I learned using GitHub Copilot for spec-driven development. I'll use the content from my previous article, Secure Medallion Architecture Pattern on Azure Databricks (Part I) , as a technical specification to extract implementation details and generate two outputs: Terraform code for infrastructure, platform configuration, and deployment Databricks Declarative Automation Bundles for jobs, pipelines, and other deployment-ready workload resources I've tried not to overfit the prompts within the skills I've developed, so they remain portable to other technical articles, not just the one mentioned in this blog. Separate the platform from the workload When I started the design, I decided to modularise the automation scripts by separating the platform from the actual data platform workloads. I assigned networking, storage, identities, secret scopes, and workspace configuration to Terraform, while Databricks notebook runs, job clusters, pipelines, and environment-specific deployments were developed within Databricks Declarative Automation Bundles (formerly known as Databricks Asset Bundles). That may sound obvious, but it's exactly where generated code often goes wrong. Without explicit instructions, AI tools tend to blur these boundaries and produce one oversized block of configuration. That's why my Copilot skill needs to enforce a clear contract by: Infer the architecture from the article Identify what is explicit and what is assumed Emit Terraform only for infrastructure concerns Emit bundle files only for workload concerns Leave placeholders for anything the article does not specify That last point is critical. A blog post or low-level technical specification is not a source of truth for account IDs, hostnames, catalog names, secret values, or subnet IDs. Good automation should never fabricate those values. Instead, I decided to produce a starter implementation with TODO markers wherever environment-specific values are required. Skills are a great way to get more consistent, repeatable output across runs, so I decided to use them for this project. I could have used one of the tools listed in the table below, but I chose to go my own way, into developing a Spec-Driven Development (SDD) framework which I hope it will carryon improve with time. Tool Creator Type Link Description GitHub Spec Kit GitHub Open source github/spec-kit Turns feature ideas into specs, plans, and task lists before any code is written. Works with multiple AI coding agents. Specification first, code as generated output. BMAD Method BMad Code LLC Open source bmad-code-org/BMAD-METHOD An AI-driven agile framework with specialised agents covering the full lifecycle from ideation to deployment. Scale-adaptive — adjusts planning depth from a bug fix to an enterprise system. OpenSpec Fission AI Open source Fission-AI/OpenSpec Lightweight spec layer that sits above your existing AI tools. Each change gets a proposal, specs, design, and task list. No rigid phase gates, no IDE lock-in. What are skills, and why are they a good fit? Skills are essentially reusable prompt modules that aim to force LLMs to produce repeatable answers. Within a skill, I define the behavior and then attach supporting resources or scripts so Copilot can perform the task consistently. That means a skill can do more than just "write some code." A skill can define a repeatable workflow like this: Fetch the blog URL Extract headings, paragraphs, and code snippets Normalize the article into a lightweight implementation spec Decide what belongs in Terraform Decide what belongs in the Databricks bundle Generate files in a predictable project structure Produce a TODO.md file for unresolved values This approach turns Copilot from a generic assistant into a specialized code-conversion tool. However, there are some constraints I had to be mindful of when developing skills: Context window limits. The model has limited space to read instructions, process input, and generate output. Long prompts can cause files to be cut off or steps to be skipped. Non-determinism. Output may vary between runs, even with strict instructions. I always lint, validate, and review the diff before committing. Boundary leakage. Models may invent plausible but incorrect values. The TODO.md pattern must be enforced as a rule, not a suggestion. Model and tool drift. Copilot's model and tool surface change over time. I use example inputs and outputs as repeatable sanity checks. Maintainability. A skill is code-as-prompt and will age with the platforms it targets. I keep skills narrowly scoped so they stay easy to update. I'll explain the TODO.md file in more detail later in this post. The GitHub repo The repository can be found at the link MarcoScagliola/CopilotBlogToCode Below you will find a function I have added that, when invoked, deletes all the files produced by the skills, so you can test the repo from a clean state. python .github/skills/blog-to-databricks-iac/scripts/reset_generated.py --force; If you want to tried it out, please clone and try it on your copy. In GitHub Copilot, I usually keep: Model as Auto Foer the configure tools I keep just the built-in tools selected. Below you can find the prompt that I use to run the skills and have the blog analysed. Use the blog-to-databricks-iac skill on this article: https://techcommunity.microsoft.com/blog/analyticsonazure/secure-medallion-architecture-pattern-on-azure-databricks-part-i/4459268 Inputs: workload: blg environment: dev azure_region: uksouth github_environment: To make this more repeatable and less manual, I've added a prompt file at run-blogToDatabricksIac-selected-tools.prompt.md, which can be run directly from VS Code by opening the file and clicking the run button at the top. Feel free to experiment with it and let me know what you think. Further instructions on how to use the repo are available READ_FIRST.md. Following you will find the exact repository setup I used for this workflow, starting with my initial configuration and ending with the final directory structure and files. 1. Create a new GitHub repository and clone it locally I started by creating a new repository on GitHub, then cloned it to my local machine so I could add the Copilot skill, Terraform scaffolding, and Databricks bundle files in a centralized location. git clone https://github.com/YOUR-ORG/blog-to-databricks-iac.git cd blog-to-databricks-iac This approach keeps the workflow organised from the start: the repository exists on GitHub first, and the local clone becomes the working directory for all subsequent setup steps. 2. Create the GitHub skill folder structure (first iteration) GitHub Copilot skills are file-based and centered on a SKILL.md file inside a skill folder. GitHub's current pattern places these under .github/skills/ . I used the script below to create the folder hierarchy for my initial integration. mkdir -p .github/skills/blog-to-databricks-iac/scripts mkdir -p .github/skills/blog-to-databricks-iac/templates mkdir -p infra/terraform mkdir -p databricks-bundle/resources mkdir -p databricks-bundle/src This script generates the structure depicted below. 3. Add the main skill definition Next, I created the SKILL.md file at .github/skills/blog-to-databricks-iac/ . The orchestrator decides what happens and in what order, while each specialist decides what its own file should contain (as an example the Terraform specialist owns the Terraform, the bundle specialist owns the bundle, and so on). In practice, SKILL.md turns Copilot from a general assistant into a domain-specific generator for this repo. GitHub documents this SKILL.md-based structure as the foundation of agent skills. My first iteration of .github/skills/blog-to-databricks-iac/SKILL.md> was very simple and can be found here. 4. Add a script to fetch and normalize the blog article Next, I created a Python script that the main orchestrator SKILL.md invokes to read the blog article. This script is stored at .github/skills/blog-to-databricks-iac/scripts/ and named fetch_blog.py . Within SKILL.md , the script is invoked as shown below. ### 1. Fetch article ```bash python .github/skills/blog-to-databricks-iac/scripts/fetch_blog.py "<url>" ``` If fetch fails, stop and return the fetch error output. Do not retry; surface the error to the user and wait for guidance.</url> The script validates the URL, fetches the HTML with a 30-second timeout, and uses a spoofed Mozilla User-Agent to avoid being blocked by CDNs (Content Delivery Networks). It reads through the HTML one tag at a time, flagging when it enters relevant sections like paragraphs, headings, or code blocks, and buffering text until the tag closes. Before storing anything, it cleans the text by decoding HTML objects, collapsing whitespace, and trimming edges. As it parses, the script also scans for cloud platform keywords: AWS, S3, Azure, ADLS, GCP, Google Cloud. The first match wins; if none are found, it returns unknown. This is a quick heuristic, not authoritative. Finally, it outputs clean JSON with the extracted data: title, headings, paragraphs, code blocks, and cloud hint, capped at reasonable sizes to keep the output manageable. If anything goes wrong, such as a network error, timeout, bad HTML, or empty content, the script exits cleanly with a structured error message, making it easy to integrate into larger workflows without surprises. The Python scrip can be found here. 5. The output and output contract Now I needed to think about the output I wanted GitHub Copilot to deliver through the skills. To reiterate, I needed the following: File Name Description README.md This is the operator-facing runbook that turns the generated artifacts into a working deployment. It contains no unresolved placeholders and no embedded credentials. The header summarizes the architecture and links back to the source blog. A prerequisites section lists required Azure access, Entra permissions, GitHub Environment setup, and local CLI versions. It includes tables of always-required GitHub secrets and variables, plus conditional ones based on deployment mode. Step-by-step numbered sections walk through bootstrapping the deployment principal and populating the GitHub Environment. Workflow blocks describe each Terraform validation, infrastructure deployment, and DAB deployment step, including file paths, triggers, and outputs. A commands section lists the exact Terraform and Databricks bundle sequences to run. Finally, assumption notes point the operator to TODO.md and SPEC.md for context. TODO.md The operator's checklist of remaining tasks. It uses a strict five-section format (Heading, What this is, Why deferred, Source, Resolution, Done looks like) with no commands or code, only concepts and decisions. Each section captures a different layer of post-deployment work, pre-deployment tasks like RBAC roles and GitHub secrets, deployment-time inputs like region and environment, post-infrastructure setup like Key Vault secrets and external locations, post-DAB work like Unity Catalog grants and job schedules, and architectural choices the orchestrator couldn't make (network posture, schemas, partitioning). Every entry comes from something the article left unstated, plus the universal post-deploy work for any Databricks deployment. The operator works through TODO.md sequentially, resolving each item before the system is production-ready. SPEC.md The structured, source-faithful read of the blog article, organized by checklist. Every item is marked as a stated value, inferred from code or diagrams, or "not stated in article." It includes architecture details, Azure services configuration, Databricks setup, data model, security and identity requirements, and observations. SPEC.md is the single source of truth that Terraform and DAB generators read from, TODO.md is populated from every "not stated" entry, and README.md references it for assumptions. This ensures the deployment is built on documented decisions, not hidden assumptions. Together, these files create a clear boundary: SPEC.md answers what the blog says, TODO.md captures what's missing or must be decided, README.md tells you exactly how to deploy. This split is enforced by validation rules that fail if any content duplicates across the three files. To make these files as repeatable as possible, I needed two things: Two templates, one for README.md and one for TODO.md , that the orchestrator fills in from SPEC.md at generation time. A broader delivery contract, output-contract.md , which lists the five files the orchestrator must produce. README.md and TODO.md are two of those five, and the templates are how they get produced. The output-contract.md file defines a strict, ordered format that the agent must follow when transforming a blog article about Databricks-on-Azure architecture into a runnable repository. The first commit was deliberately minimal, as you can see from the file available here. No leaf-skill routing, no repo-context.md, no GitHub Actions workflows, no validation rules, no entry-field templates for TODO.md . That commit's single job was to lock down the shape of the output: what gets produced and in what order. Every commit since has refined how to produce that shape without changing what gets produced. Putting the contract in the very first commit gave every later change a fixed reference point. Every leaf skill, generator script, and validation rule I've added since has fit into one of its five sections. The pipeline has changed; the deliverables haven't. The structure of the GitHub repo at commit 17ab443 can be see in the pictorial below. 6. The README.md and TODO.md templates After iteratively working on the orchestrator, a clear pattern emerged, the code-generation paths were kind of stable, but the documentation outputs weren't. Every run produced README.md and TODO.md from scratch in free-form Markdown. Across runs, the same content kept drifting. Section ordering changed between runs and the explanation of GitHub Environments was rewritten with subtle wording differences. RBAC roles appeared sometimes as lists, sometimes in prose, sometimes split across sections. Universal post-deploy actions (create the secret scope, populate the vault, set up Unity Catalog grants) were re-derived every time, occasionally with steps missing. The root cause was that the orchestrator was treating durable, universal content as if it were per-run content. So I've decided to add two templates: README.md.template and TODO.md.template. Templates separate universal content (RBAC, TODO sections, GitHub setup) in the template from per-workload content (catalog names, credentials) substituted from SPEC.md. This delivers consistency across runs. The README and TODO are structurally identical, so readers can navigate them intuitively. Universal content is correct by construction; I write it once, review carefully, and every run inherits that quality. Validation also becomes more precise, and the agent's job shrinks from open-ended writing to mechanical substitution, which is easier to validate and maintain. Templates introduce clear vocabulary: {placeholder} is filled by the orchestrator at generation time, by the deployer at run time. Finally, templates enforce traceability: every "not stated in article" entry in SPEC.md automatically becomes a TODO entry via the from SPEC.md slot, making this an automatically-enforced rule. I'm invoking the templates in the orchestrator as shown below. The Git commit with this code can be found at this link. ### 3.1 Generate README from template Load the template: `.github/skills/blog-to-databricks-iac/templates/README.md.template` ### 3.2 Generate TODO from template Load the template: `.github/skills/blog-to-databricks-iac/templates/TODO.md.template` 7. The output of the fetch_blog.py file and the interaction with the orchestrator When the orchestrator invokes fetch_blog.py , the script produces a JSON output and passes it back to the orchestrator. The orchestrator then reads the JSON document into its working context and maps each field onto an analysis checklist. The title and meta description establish the article identity and scope. Headings with their levels reveal the structure, helping the agent locate sections about architecture, security, data flow, and naming. Paragraphs provide evidence for stated values like regions, resource types, and RBAC models. Code blocks become the source of inferred values. As an example, a Terraform snippet might reveal SKU choices or naming patterns not mentioned in the text. These inferred values get tagged "inferred from code snippet" when recorded. The cloud hint acts as a sanity check that the article actually describes an Azure architecture. For every checklist item, the agent records either an extracted value or the literal string "not stated in article". This becomes SPEC.md , the single source of truth for everything downstream. SPEC.md drives every subsequent step. Steps 3 through 7 (the Terraform module, workflows, and Databricks bundle generators) read architectural decisions from it. Step 8 then produces TODO.md by converting every "not stated in article" entry into a TODO item the operator must resolve before deployment. What I find worth pointing out is how little the output contract has actually moved since that very first commit. The implementation underneath has changed completely. Leaf skills emerged, generator scripts came in, validation rules got added, a soft-delete state machine showed up to handle Key Vault recovery. None of those existed at the start. But what the orchestrator delivers, the list of files it puts on disk, has stayed exactly the same. We have a much larger SKILL.md today that still mirrors the initial five-item output list. The contract itself has changed by exactly one line: the addition of "Design of the architecture" to section 5. SPEC.md : the structured, source-faithful read of the article, organised by the analysis checklist ( link ) TODO.md : the operator's checklist of everything the article didn't specify, plus the universal post-deploy actions ( link ) Terraform code under infra/terraform/ : the platform layer with networking, storage, identities, Key Vault, workspace ( link ) Databricks Asset Bundle under databricks-bundle/ : the workload layer with jobs, entry points, environment configuration ( link ) README.md : the operator runbook, with the architecture design diagram embedded ( link ) If the JSON contains an error, the orchestrator stops immediately. Per the skill rule "If fetch fails, stop and return the fetch error output. Do not retry," the error surfaces to the user rather than propagating downstream. So the script's output is the raw evidence pack: title, structure, prose, code, cloud hint. The agent uses it to fill the architecture spec, which parameterises every generated artifact. At this point the fetch_blog.py output is sent to Step 2 of the orchestrator, as shown in the code snippet below. ### 2. Analyse article Analyse the fetched article against the structured checklist in `.github/skills/blog-to-databricks-iac/references/blog-analysis-checklist.md`. The analysis covers the article text, diagrams, screenshots, and code snippets. And, much later in the orchestrator, Step 8 closes the loop by turning everything that's been recorded into the two operator-facing documents: ### 8. Generate README and TODO from templates Use the templates in `.github/skills/blog-to-databricks-iac/templates/`: - `README.md.template` -> `README.md` - `TODO.md.template` -> `TODO.md` 8. How this actually came together What I've described so far is how the orchestrator works currently. The reality of building it was much cumbersome , but also fun. I got from the first version to the current one by iterating. Rerun the orchestrator, find the defect, identify the rule that would have caught it, add the rule to the skill that owns the artifact, rerun. The reason I'm calling this out now, before walking through the rest of the pipeline, is that everything from this point on is a story about a specific lesson learned that way. The leaf skills exist because a single SKILL.md got too dense. The restricted-tenant guardrails exist because the deployment failed against a tenant that couldn't read Microsoft Graph. The validation harness exists because prose rules weren't catching the regressions that mattered. The soft-delete state machine exists because the same vault name kept colliding with a previous deploy. None of these rules were present from day-one. So in the next sections I'll walk through how the pipeline actually matured: how the single skill split into a graph, what the inner regenerate-fix loop felt like in practice, the day the project pivoted to support restricted tenants, the bugs that became rules, and the Key Vault soft-delete state machine that closed the project out. 9. From a single skill to a skill graph When I started, everything lived inside a single SKILL.md . It was simpler that way, and to be honest, at that point I didn't yet know which rules would actually matter. But as I kept rerunning the orchestrator on the article, a pattern emerged. Each rerun produced something that broke in a slightly different way, and the fix always belonged to a very specific concern: Terraform authoring, bundle structure, workflow generation, or the orchestration logic itself. Stuffing the rules for all of them into one file was making the orchestrator unreadable and, worse, was silently dropping rules when the context window got tight. So I split it. The orchestrator stayed at the top, kept routing the work and validating the result, and each concern got promoted to its own leaf skill. The Databricks bundle skill itself ended up needing one more split a few days later, it had got too dense, so I broke it into two leaves: databricks-yml-authoring ( link ) Python-entrypoints ( link ) The diagram below shows the shape the repo has today. The orchestrator now does almost no authoring. It owns the sequence of steps, the contract, and the validation gates, while everything else is delegated. This was the single biggest readability win. I wish I'd done it earlier. The REPO_CONTEXT.md is one extra node in that diagram that I want to call out But I'll come back to later in section 12. 10. The inner loop: rerun, fail, fix the skill If I had to describe the middle of this project in one sentence, it would be: every commit was a regeneration. I'd run the orchestrator end-to-end against the article, inspect the generated Terraform, the bundle, the workflows. I'd find a defect, identify the rule that would have prevented it, add that rule to the skill that owns the artifact, then rerun. As shown in the image below. This loop is what I think people miss when they treat AI-generated infrastructure code as a one-shot. The first run is never the deliverable. The deliverable is the skill that produces good runs. The generated files are disposable and can always be reproduced. The skill is what carries the knowledge forward. I had to actively resist the temptation to fix bugs in the generated code directly. Patching infra/terraform/main.tf by hand fixes today's run but not tomorrow's, because the rule that would prevent the bug doesn't exist anywhere. So I made it a discipline: never edit the output, always edit the skill, then regenerate. 11. Restricted-tenant compatibility The bug was simple to describe and brutal to fix: the deployment principal in the target tenant couldn't read Microsoft Graph. Any Terraform data source that resolved an Entra name to an object ID at plan time (e.g., azuread_user , azuread_group , azuread_service_principal ) blew up at terraform plan. My first instinct was to think "I just give the principal Graph permissions". But in a lot of real environments this is not possible. The principal that runs your IaC is governed by a security team, the team has a policy, and the policy says no Graph reads. The pivot was getting the skill to produce Terraform that never reads Graph. Object IDs are inputs, not lookups. They come in as trusted secrets, the workflow exports them as TF_VAR_* , and Terraform consumes them as variables. No data " azuread_* " block is allowed in the generated code, ever. I thought this was a simple fix. It wasn't. It cascaded into about six other things: App Registration vs Service Principal object IDs. The workflow was being given the wrong one. Role assignments need the Enterprise Application (Service Principal) object ID, not the App Registration object ID. The two are different objects in Entra with different IDs. I encoded the distinction in the skill as *_SP_OBJECT_ID (the Service Principal) versus *_CLIENT_ID (the App Registration's application ID). Naming carries the meaning now, so the wrong value is hard to pass. Single-principal mapping. In some tenants you only have one principal and it has to play both deployment and runtime roles. The skill grew a layer_sp_mode = existing input so the generator stops trying to create a new Service Principal and reuses the deployment one instead. Key Vault access policies, gone. Access policies were Graph-touching, and not all tenants support them anyway. The skill switched fully to RBAC role assignments (Key Vault Secrets User, and so on). A few cascading bugs followed, but this was the right call. It took some time to harden the Terraform skill against everything the restricted tenant was throwing back. Each iterations had the same shape, each orchestrator runs, hits a fresh provider error, I add the rule, run again, hit the next one. The commit subjects from that run are basically a transcript of the conversation I was having with the platform. 12. The bugs that became rules There are three bugs that I believe are worth telling the story of, because they each illustrate a slightly different lesson. The HCL trim() arity bug. The generator emitted trim(var.something) in a validation block. HCL's trim() takes two arguments, not one. The function I actually wanted was trimspace() . This is the kind of bug that any human would catch in a code review in two seconds, and which the model produced confidently because the shape of the call looked right. I added the rule to the Terraform skill ("for whitespace trimming use trimspace, never trim") and the bug never came back. Lesson: even for trivial syntactic mistakes, the fix belongs in the skill. The variable shadowing bug. The deploy workflow had a job-level env: block that set TF_VAR_key_vault_recover_soft_deleted to a static value. A detection step earlier in the workflow was supposed to compute the right value at runtime and write it via $GITHUB_ENV . The problem is that GitHub Actions resolves job-level environment variables before $GITHUB_ENV writes take effect, so the static value always won and the dynamic one was silently ignored. The fix was to never set the recovery flag at job level. It must be written in the detection step, on every code path, including the trivial "no recovery needed" path. Lesson: state must be explicit, not inherited. If a flag has three possible meanings, three code paths must each write it. The hardcoded -platform suffix. The workflow had a shell-side suffix that someone (let's be honest, the model) had invented to make the resource group name "look right". When recovery logic started running and the workflow looked for the canonical resource group, it looked for -platform instead of whatever the Terraform locals.tf actually emitted. The result was that the recovery handler was happily reaching past the real resource group and into a different one. I made it a rule in the orchestrator: workflow-invented suffixes are not permitted. Naming is owned by Terraform's locals.tf . There are seventeen more defects in the catalogue, and the pattern is the same in every case. The bug surfaces, the rule gets written, the rule lives in the skill that owns the affected artifact. There is no implementation-learnings.md in the repo. There used to be, but I've deleted it because a tracked log of past bugs, sitting next to a skill that's already supposed to encode the lessons from those bugs, is a duplication waiting to drift. I believe that if the rule is in the skill, the log is redundant. If the rule isn't in the skill, the log is an evidence that I haven't finished the work. Either way, the right place for bug history is git log. 13. Splitting "the skill" from "this repo's defaults" I then wanted the orchestrator to be portable, but every run kept needing the same handful of decisions. Which Azure region by default? Which environment names? Which catalog naming convention? These weren't part of the article. They weren't part of the Terraform skill either. They were specific to this repository's opinion about how things should be deployed. If I baked them into the orchestrator, the orchestrator stopped being portable. If I left them out, every run produced unhelpful "not stated in article" entries for the same five universal decisions. The answer was a new file called REPO_CONTEXT.md stored in the repo root. It's read by the orchestrator before generation and it carries the defaults that are owned by the repo, not by the skill. The split looks like this in practice: SKILL.md answers the question "how do I turn an article into a runnable repo?" It is portable. REPO_CONTEXT.md answers the question "what does this repo default to when the article doesn't say?" It is local. Cloning the orchestrator into another GitHub project is now a clean operation. You take the skill, you write your own REPO_CONTEXT.md , and the same generator produces output appropriate to your environment. 14. The Validations Most of the rules I'd written into the skills were prose. "Don't invent suffixes." "Object IDs are inputs, not lookups." "Every required Terraform variable must have a matching TF_VAR_* in the workflow." The model is good at following prose rules most of the time. So a few of the most regression-prone rules became executable. The most important one is scripts/validate_workflow_parity.sh . Every variable declared in infra/terraform/variables.tf must appear as a TF_VAR_* export in the deploy workflow. The script greps both files, diffs the sets, and exits non-zero if they don't match. It is run at the end of generation. If it fails, the run failed, even if everything else looks fine. This caught real bugs. The most embarrassing was a variable I'd added to variables.tf and forgot to wire through the workflow. Terraform plan would prompt interactively for it on a non-interactive runner, and the run would hang. The rule of thumb I've ended up with is: prose rules are the default, but if a rule has been violated more than twice, it gets promoted to an executable check. There's a short list of those checks now, and it's the load-bearing one. 15. Key Vault soft-delete state machine Key Vaults in Azure have soft delete on by default. When you delete a vault, it sticks around for ninety days in a "soft-deleted" state. If you try to create a vault with the same name in the same subscription during that window, the deploy fails. The right behaviour is to recover the soft-deleted vault, not create a new one. The first version of my recovery handler covered exactly one case: if the vault is soft-deleted, recover it. This worked the first time I ran it. The second time, the recovered vault came back into the previous resource group, not the new one I had just created. Terraform then tried to create a new vault in the correct resource group and failed because the name was already taken globally. The handler had no concept of "the recovered vault is in the wrong resource group." So I added that case. The third time, the previous resource group itself was gone, and the handler was looking for it to verify the move. So I added that case too. By the end, the state machine had three distinct cases and two preconditions, as shown in the diagram below. The reason I keep coming back to this state machine is that it captures something that I think is generally true about agent-generated infrastructure code. The happy path is easy and meaningless, while the value is in the failure modes. The first version that worked on a clean tenant was about ten lines of bash. The version that works on a tenant that has been deployed-into and partially-torn-down five times is six times longer, and every additional line of it corresponds to a real environmental condition that I had to learn the hard way. 16. What I've learned so far I'm not going to pretend the full list of principles below was clear to me on day one. Every single one of these was learned by getting it wrong first. Looking back at the history, though, they are the ones that survived contact with reality. The contract precedes the implementation. output-contract.md was committed before any generator existed. Locking the shape of the deliverable first meant every later change had a fixed reference point. Generators, not stencils. Workflows are produced by Python scripts that take parameters and emit YAML. When restricted-tenant logic and the soft-delete state machine arrived, they needed conditional structure that a static template can't express. Every bug becomes a rule. Patching the generated code is a tax on tomorrow's run. While patching the skill is an investment. Each concern has a clear owner. The orchestrator routes, the leaves author, and the repo context holds the local defaults. Restricted-tenant compatibility is non-negotiable. No Microsoft Graph reads from generated Terraform. Object IDs are trusted inputs. Single-principal mapping is supported. Naming is owned by Terraform. No suffixes invented in shell. The validation harness enforces this. State must be explicit, not inherited. Every workflow run writes its own flags. No reliance on env defaults from a previous step or a previous run. Validation is executable when a rule has been violated more than twice. Prose rules are the default. Promotion to a script is earned. Operator docs describe concepts, not commands. Command syntax ages out, while conceptual descriptions don't. The TODO template enforces this rule. Add strong testing at the end of the process, once all the files are generated. Each run may produce slightly different output and introduce bugs, even if the previous run was successful. End-to-end runs against dirty tenants are the truth. The acceptance test isn't a clean-room deploy. It's a deploy into a tenant that has soft-deleted vaults, lingering RGs, and existing role assignments. Until that works, the project isn't done. From time to time, skills need to be reviewed and consolidated. The summary above of the journey is the one I find most useful to share when people ask whether this approach actually goes anywhere. From an empty repo to a generator that produces a deployable, restricted-tenant-compatible infrastructure-as-code repository from a blog URL, with executable validation and a recovery state machine that survives a previously-deployed environment. The first commit was an empty workspace. The last commit was the one where the same orchestrator, run against the same blog, against a tenant carrying state from five previous runs, deployed cleanly with no manual intervention. That is what I what I was aiming to achieve when I started! Thanks for reading.Resilient by Design: Azure Databricks Disaster Recovery Strategy
Introduction: From Recovery Plans to Resilience Strategy As organizations increasingly rely on Azure Databricks for mission-critical analytics and data engineering workloads, the need for robust disaster recovery (DR) strategies becomes paramount. These platforms are no longer just analytics engines, they power real-time decisions, AI models, and core business operations. Yet many organizations still approach Disaster Recovery (DR) as a reactive safeguard rather than a strategic capability. Resilience today is not about “if something fails,” but about ensuring continuity, trust, and performance under any condition. A modern DR strategy must therefore evolve beyond backup configurations and failover scripts. It must align with business priorities, regulatory requirements, risk tolerance, and operational maturity to become a core pillar of the enterprise data platform. In this context, organizations are increasingly adopting architecture patterns that enable cross-region resilience for the Azure Databricks Lakehouse. This pattern includes synchronizing Unity Catalog objects—catalogs, schemas, tables, views, function, models, and volumes—across regions, combined with scalable data movement mechanisms and secure data access approaches such as Delta Sharing and high-performance transfer tools. To help organizations operationalize this approach today, we have defined a structured strategy for synchronizing Unity Catalog objects and associated data across regions, enabling a resilient-by-design Azure Databricks architecture. This post focuses on that approach, outlining the key architectural patterns, strategic considerations, and practical implementation steps required to design and enable cross-region resilience. In October 2025, Databricks announced a Managed Disaster Recovery solution, developed in collaboration with Capital One, which includes managed replication, customer-specified failover, and read-only secondary capabilities. The approach outlined in this post serves as a complementary, customer-managed pattern, providing a practical and production-ready path for organizations to achieve robust disaster recovery and business continuity while Databricks continues to expand its native DR capabilities. Why Disaster Recovery for Azure Databricks is Different Traditional Disaster Recovery approaches do not fully apply to modern Lakehouse platforms. In Azure Databricks, resilience must account for: Tight coupling between data, compute, and metadata (Unity Catalog) Distributed pipelines (batch, streaming, ML) Decentralized workspace ownership and rapid platform growth This makes disaster recovery not just an infrastructure concern, but a data platform design challenge. Figure 1. Main Disaster Recovery Considerations Understanding the Fundamentals: RTO, RPO, and DR Trade-offs Before defining a disaster recovery strategy, it is essential to understand the core concepts that drive design decisions. Recovery Time Objective (RTO) defines how quickly a system must be restored after a disruption; while Recovery Point Objective (RPO) defines how much data loss is acceptable. These two metrics directly influence the architecture, cost, and complexity of any DR solution. As illustrated in Figure 1, there is a clear trade-off between cost and recovery performance: Active-active (hot) architectures, minimize downtime and data loss but come at a higher cost. Warm standby provides a balance between cost and recovery time. Cold DR is cost-efficient but results in longer recovery times and higher data loss risk. Understanding these trade-offs is critical to aligning DR strategy with business expectations. Understanding the Fundamentals: RTO, RPO, and DR Trade-offs Before defining a disaster recovery strategy, it is essential to understand the core concepts that drive design decisions. Recovery Time Objective (RTO) defines how quickly a system must be restored after a disruption; while Recovery Point Objective (RPO) defines how much data loss is acceptable. These two metrics directly influence the architecture, cost, and complexity of any DR solution. As illustrated in Figure 1, there is a clear trade-off between cost and recovery performance: Active-active (hot) architectures, minimize downtime and data loss but come at a higher cost. Warm standby provides a balance between cost and recovery time. Cold DR is cost-efficient but results in longer recovery times and higher data loss risk. Understanding these trade-offs is critical to aligning DR strategy with business expectations. Designing for Resilience: A Phased Disaster Recovery Approach Disaster recovery has evolved beyond a one-time setup into a structured, lifecycle-driven capability. Leading organizations design resilience intentionally, implement it systematically, and continuously validate it to ensure ongoing effectiveness. The framework outlined below provides a practical and strategic approach to operationalizing disaster recovery in Azure Databricks environments, bridging the gap between architectural intent and true operational readiness. Figure 2. Different Phases of Azure Databricks Disaster Recovery Phase 1: Discovery & Assessment A resilient disaster recovery strategy starts with clarity—yet in many Azure Databricks environments, that clarity is often missing. As platforms evolve, clusters multiply, jobs are duplicated, and data assets grow, making it increasingly difficult to answer a simple question: what do we actually have, and how critical is it? The Discovery phase addresses this by establishing a single, authoritative view of the platform. By consolidating all assets, dependencies, and usage patterns into a structured baseline, organizations can move from fragmented visibility to informed decision-making. This approach aligns closely with the concepts outlined in “From Chaos to Clarity: Your Databricks Workspace on a Single Pane of Glass”, where establishing a comprehensive inventory becomes the foundation for governance, optimization, and ultimately resilience. This foundation enables teams to identify what matters most, define appropriate RTO and RPO targets, and understand the dependencies that will ultimately shape their disaster recovery strategy. Outcome A clear, data-driven baseline of the environment—enabling confident workload prioritization and effective disaster recovery design. Phase 2: Strategy & Design Once visibility is established, the next step is making deliberate design choices—balancing resilience, cost, and complexity. At this stage, organizations define how their platform should behave under failure. This typically starts with selecting a multi-site deployment pattern, in which two primary approaches are commonly adopted: Active–Active, where both regions are fully operational and serve live workloads Active–Passive (Warm Standby), where a secondary region is pre-provisioned and activated only during failover Active–active architectures provide near-zero downtime and minimal data loss but come with increased cost and architectural complexity. Active–passive patterns offer a more cost-efficient alternative, with slightly higher recovery times depending on how failover is orchestrated. Beyond selecting the deployment pattern, a key architectural decision is how data is replicated across the Medallion architecture (Bronze, Silver, Gold). Our approach introduces a set of practical scenarios that allow organizations to tailor resilience based on both workload criticality and recovery requirements. A common starting point is aligning the DR strategy to workload tiers, such as: Tier 1 (Mission-critical): Active–Active with full replication Tier 2 (Business-critical) : Active–Passive with partial replication Building on this, organizations can further refine their approach by defining how data is replicated across the Medallion layers: Full replication (Bronze, Silver, Gold) , i.e. fastest recovery at highest cost; Bronze-only replication, lower cost, with re-computation required during recovery; Gold-only replication, optimized for consumption-focused use cases. This combination of workload tiering and Medallion replication strategies enables a flexible, fit-for-purpose approach to disaster recovery, which balances performance, cost, and operational complexity. Below we demonstrate, as an example, two representative patterns: (a) Active–Active architecture, where data pipelines operate in continuous trigger mode across regions, enabling near real-time synchronization; and (b) Active–Passive architecture, where all layers are replicated using a clone-based approach and activated on demand during failover. These scenarios highlight how organizations can balance recovery performance and cost by adjusting both the deployment model and the depth of data replication. 3. Active - Active Scenario - Continuous Trigger Mode Within the active–passive model, multiple variations can be applied, ranging from full replication of all medallion layers to more selective approaches (such as replicating only Bronze or Gold layers). This flexibility allows organizations to further balance recovery performance, cost, and operational complexity. 4. Active - Passive Scenario - Clone All Layers Mode Phase 3: Disaster Recovery Implementation & Enablement With the strategy defined, the focus shifts to translating design into a repeatable and operational solution. At this stage, resilience is no longer conceptual, it is embedded into the platform through automation, data replication, and standardized deployment patterns. From Strategy to Architecture At a high level, the DR architecture spans both the primary and secondary Azure regions, ensuring that all critical components can be either replicated or recreated: Control plane synchronization: Users, groups, and workspace assets are replicated using SCIM, Terraform, and CI/CD pipelines. Workspace and metadata portability: Jobs, notebooks, and configurations are defined as code and deployed consistently across regions. Data layer replication: Managed data, external data, and streaming checkpoints are synchronized using deep clone operations. This layered approach ensures that the platform can be reconstructed end-to-end, not just partially recovered. Unity Catalog-Driven Replication A critical aspect of the implementation is the replication of Unity Catalog metadata and associated data assets. This includes: Synchronizing catalogs, schemas, tables, views, functions, and volumes Using Delta Sharing to expose datasets across regions Leveraging deep clone and storage replication to ensure data availability Recreating external and managed locations in the target region By combining metadata synchronization with data replication, the target environment becomes a fully functional mirror of the source. 5. Unity Catalog Focused DR Mechanisms Operationalizing with a DR Pipeline To make this repeatable, the architecture is supported by a DR pipeline that orchestrates the process end-to-end: Synchronize schemas and Unity Catalog structures Perform deep clone of Delta tables Recreate views and dependent objects Provision volumes and copy associated data Ensure consistency across storage layers (e.g., ADLS via AzCopy) This pipeline can operate either continuously or on demand, depending on the selected DR pattern. 6. Azure Databricks DR Replication Workflow Outcome A fully implemented disaster recovery solution where data, metadata, and platform components are consistently synchronized, enabling rapid and reliable activation of workloads in a secondary region. Phase 4: DR Drill: Validation, Operations & Continuous Improvement A disaster recovery strategy is only valuable if it works when needed. This phase focuses on validating, operating, and continuously improving the DR solution to ensure it meets business expectations. Failover & Failback in Practice In a real failure scenario, the transition to the secondary region must be simple, predictable, and fast. A typical failover process includes: Detecting primary region unavailability Executing a final synchronization (if possible) Redirecting connections to the DR workspace Resuming operations without requiring code changes Equally important is failback, once the primary region is restored: Re-synchronizing data from DR to primary Switching pipelines and configurations back Gradually restoring normal operations Because infrastructure and metadata are standardized, this process becomes operational rather than reactive. Operating DR as a Continuous Capability Beyond failover, DR must be actively managed as part of daily operations: Monitoring & Alerting: Track job failures, performance bottlenecks, and system health Governance & Change Management: Maintain consistency between environments using IaC and version-controlled pipelines Continuous Optimization: Adjust replication strategies, scaling, and performance as workloads evolve This ensures the DR solution remains aligned with both technical and business changes over time. Ensuring Performance, Integrity, and Security A production-ready DR solution must also guarantee: Performance & Scalability: Optimize compute, autoscaling, and data transfer to handle recovery scenarios efficiently Data Integrity & Consistency: Validate schema synchronization, monitor replication jobs, and ensure parity between regions Security & Compliance: Enforce consistent access controls, secure credentials, and enable audit logging across environments Outcome A validated and continuously evolving DR capability—where recovery processes are tested, monitored, and improved over time, providing confidence to both technical teams and business stakeholders. Key Takeaways and Closing Thoughts Resilience in modern data platforms is no longer defined by how quickly systems can recover, but by how effectively they are designed to withstand disruption in the first place. Azure Databricks, as a core engine for data, analytics, and AI, requires a disaster recovery approach that extends beyond infrastructure—one that treats data, metadata, pipelines, and governance as a unified system. By combining a structured discovery phase, a strategy aligned to workload criticality, and automated, repeatable implementation patterns, organizations can move from reactive recovery to resilience by design. This not only reduces risk, but also ensures that critical data workloads remain available, trusted, and performant when it matters most. The approach outlined in this post provides a practical and flexible way to enable cross-region resilience today, while also complementing the managed disaster recovery capabilities expected to be introduced by Databricks. As we anticipate the availability of these native features, this approach offers a production-ready foundation that can extend and integrate with future platform capabilities. In a world where disruption is inevitable, the objective is no longer simply to recover—but to maintain continuity of data, decisions, and business operations with confidence. Special thank you to Vasilis Zisiadis, Dimitris Kotanis who contributed their expertise to create this material and bring it to life. Thank You Antony Bitar, Collin Brian and Jason Pereira for their support in reviewing the content.From Chaos to Clarity: Your Databricks Workspace on a Single Pane of Glass
The question that never stays answered — until now As Azure Databricks workspaces evolve, complexity creeps in unnoticed. Every Azure Databricks conversation with customers eventually lands on the same question: “What do we actually have in this workspace?” Over time, clusters multiply, jobs get cloned, warehouses are spun up for one-off demos and forgotten, and Unity Catalog keeps expanding until it’s hard to reason about. In most enterprises, each business or data science team operates its own workspace, while the central platform or operations team has little to no visibility into what’s being created or why. Teams often spend days—or weeks—trying to piece together what exists, who owns it, and the business purpose behind it, only to realize they still don’t have the full picture. And when the same question comes up next quarter, the cycle starts all over again. To address this, we built a utility that helps customers answer exactly that—by providing a single pane of glass for all Databricks assets through comprehensive cataloging and usage analysis. The utility works in two phases: Discovery and Analysis. This post focuses on the first step—the Discovery phase, where we establish a clear, authoritative inventory of everything that exists in the workspace. What the Discovery Phase delivers? Think of the Discovery phase as a workspace health assessment. Once configured against a target workspace, the utility runs in a selected mode and consolidates all discovered assets into a centralized, Delta-based repository. The result is a structured, queryable, and dashboard-ready metadata store. Behind the scenes, ten purpose-built scanners run in a tiered and parallelized architecture, enabling a fast yet comprehensive scan of the entire workspace. Scanner What is Cataloged Clusters Interactive, job, SQL — configs, policies, pools Jobs Workflows, schedules, tasks, run history Warehouses SQL endpoints, sizes, serverless settings Pipelines Delta Live Tables and their state Unity Catalog Catalogs, schemas, tables, volumes Workspace Objects Notebooks, repos, ML experiments, serving endpoints, alerts, Genie spaces Security Identity, network, data protection settings Billing 30–180 days of DBU usage by SKU and product Utilization Real CPU, memory, runtime patterns (deep scan) Spark Job Optimizer (plugin) Skew, spill, small files, broadcast hints (deep scan) Design Overview # Block Role Contents / Flow 1 Source Starting point — the Databricks environments being discovered. One or more Azure Databricks workspaces. Auth via OAuth. Outputs an authenticated WorkspaceClient to the Orchestrator. 2 Orchestrator The brain of the utility — coordinates scanning, concurrency, retries, timing. Tiered thread-pool executor, scan config (mode, billing window, UC depth, max workers). Dispatches scanners in controlled waves. 3 Tier 1 Scanners Lightweight, high-concurrency scans. Run first for quick signal. Clusters, Warehouses, Pipelines, Security. Up to 12 workers, 10-min timeout. Artifacts flow to the Centralized Repository. 4 Tier 2 Scanners High-volume scans. Controlled concurrency to avoid API throttling. Jobs, Workspace Objects (notebooks, repos, experiments, serving, alerts, Genie), Unity Catalog, Billing (30–180 days DBU). 1/2 workers, 30-min timeout. 5 Tier 3 Scanners Sequential, analysis-grade scans (deep scan only). Utilization (CPU, memory, SQL usage patterns) and Spark Job Optimizer plugin (skew, spill, small files, broadcast hints). Runs after Tiers 1 & 2. 6 Centralized Repository The catalog of truth — where all output lands, timestamped and queryable. Unity Catalog Delta tables (dashboard-ready) plus portable JSON and CSV exports for offline sharing or downstream tools. 7 Single Pane of Glass The user-facing view — insight at a glance. Pre-built Lakeview dashboard: KPI strip, inventory charts, and week-over-week trends. Refresh to see current workspace state. Why users love the view — visualization that earns its keep This is where the Discovery phase stops being just a scan and starts becoming a decision-making tool. Because everything is consolidated into a single, Unity Catalog–backed source of truth, the Lakeview dashboard delivers a genuine single pane of glass for the entire Databricks workspace. At a glance, you get: KPI strip at the top — total clusters, active jobs, UC tables, SQL warehouses, DLT pipelines, workspace objects. One glance, one number each. Inventory charts — clusters by type, jobs by schedule, warehouses by size, tables by catalog. The shape of your workspace becomes obvious. The “that doesn’t look right” moments — The idle SQL warehouse with zero queries, the cluster running the wrong runtime, the notebook floating outside any repo. These surface instantly, without hunting. Change over time — because every scan is timestamped, you can literally see your platform grow (or sprawl) week over week. In the first customer walkthrough, the platform team identified an always-on SQL warehouse with zero queries and three jobs running on the wrong compute tier—all within the first 30 minutes. That single view paid for the project. Sample Item Catalog Closing thoughts The Discovery phase isn’t about governance for governance’s sake—it’s about clarity. Before teams can optimize costs, improve performance, or enforce standards, they first need a reliable answer to a basic question: what actually exists today? By giving platform and operations teams a single, authoritative view of all Databricks assets—grounded in data, not tribal knowledge—Discovery turns guesswork into informed decisions. In the next phase, Analysis, that foundation is used to go deeper: identifying inefficiencies, risks, and opportunities to simplify and optimize the platform. But it all starts here—by finally knowing what you have. Special thank you to Antony Bitar, Collin Brian and Jason Pereira for their support in reviewing the content.
Designing a Medallion Framework — A Decision Guide
Everyone draws the same picture: Bronze → Silver → Gold. Three boxes, three arrows. Done. What that picture hides is the dozen design decisions you have to make inside each box — and the ones you make at the boundaries between them. Get those right and onboarding the 200th table feels like onboarding the 2nd. Get them wrong and you’ll be rewriting the framework in 18 months. This post is a generic walkthrough of how to think about a medallion framework on Databricks (or any other platform): what each layer should own, where the responsibilities blur, and a few opinionated patterns I’ve found worth defending The classic template - Bronze → Silver → Gold. Three layers, broadly: Press enter or click to view image in full size This template is intentionally vague — and that’s the point. The same three labels can describe a framework for a 10-table marketing pipeline and a 2,000-table enterprise lakehouse. The differences are in how you tweak the template to match your project. This post walks through the questions that drive those tweaks. There isn’t a single right answer for any of them — only the answer that fits your project’s requirements. How to read this guide For each architectural choice, I’ll frame it as: The question — the requirement you need to clarify The options — the realistic ways to answer it When each option fits — what kind of project picks which option Use this to make your tradeoffs explicit. Document the answers in your design doc. They’ll inform a hundred downstream decisions. Question 1 — Do you need a Staging layer? A Staging (stg_*) layer is a transient zone that holds just the current run’s data before it lands in Bronze. Options: No staging. Source → Bronze directly. Staging as a transient table per object, overwritten every run. Staging as a checkpointed zone (e.g., Auto Loader checkpoints + raw files in a landing path). When to pick which: The decision usually comes down to failure isolation and incremental capture clarity. If both are non-issues, you can skip it. Question 2 — How “raw” should Bronze be? This is the single biggest tweak point in the medallion architecture. The textbook says “Bronze = raw bytes.” Real projects often deviate. Options: A. Strictly raw. Source schema preserved exactly. All columns as STRING. No casting, no trimming. B. Lightly cleaned. Strong typing, whitespace trimmed, null normalization (“”, “N/A” → NULL), audit columns added. Schema stable. C. Cleansed + minor enrichment. Above plus reference data lookups, basic standardization (e.g., country codes), key normalization. When to pick which: A useful rule of thumb: the more sources and consumers you have, the cleaner Bronze should be. The cost of not cleaning compounds with every notebook downstream. If you choose B or C, you’ve shifted some traditional Silver responsibilities into Bronze. That’s fine — just be explicit about it so Silver’s contract changes accordingly. Question 3 — What does Silver actually own? Silver is the most overloaded layer in any medallion framework. Decide upfront which of these responsibilities Silver owns vs. defers to other layers: How to decide what Silver owns: If Silver is the only layer business users query, give it more — including light history and aggregations. (Common in smaller projects.) If you have a strong Gold layer with multiple marts, keep Silver narrow: business entities only, current state. If you have multiple consuming teams with different needs, push everything consumer-specific to Gold and keep Silver as the shared canonical model. The clearest signal that Silver is overloaded: you have one Silver table per source table. Silver should be organized by business entity, not by source. If they line up 1:1, you’ve effectively built “Bronze with cleaning” and skipped Silver’s real value. Question 4 — Is Gold one zone or several? The default picture shows Gold as one box. In real projects it often splits. Options: Single Gold zone. Marts and history live together. Gold-Reporting + Gold-History. Reporting marts (denormalized, aggregated, fast) separated from historized snapshots (SCD2, point-in-time, append-mostly). Gold per consumer. Separate zones per business unit, dashboard family, or external API. The cost of splitting Gold is some duplication and more pipelines. The benefit is independent SLAs — your dashboard refresh isn’t held hostage by your audit history rebuild. Question 5 — Load patterns: FullLoad vs DeltaLoad vs CDC Per source table, decide the load pattern. This decision drives staging design, watermark management, and merge logic. It’s normal to mix patterns inside the same framework. The metadata-driven approach below makes this trivial — load pattern is just a column in your config table. Question 6 — How metadata-driven should the framework be? Options: Code-per-table. One notebook per ingestion. Simple, easy to reason about, scales poorly. Hybrid. Generic ingestion notebooks for common patterns, custom notebooks for exceptions. Fully metadata-driven. Generic notebooks for every layer, behavior driven entirely by metadata tables. When to pick which: A fully metadata-driven framework has higher upfront cost but flattens the per-table cost dramatically. The break-even point is usually around 30–50 tables. Question 7 — Orchestration shape How do you fan out work across tables? Options: Sequential. One table at a time. Simple, slow. Parallel pool. ThreadPoolExecutor or Databricks Workflows fan-out. Tables run concurrently, no inter-table dependencies. DAG. Dependency-aware execution. Required when tables depend on each other. Per-layer guidance: The decision driver is whether tables in that layer depend on each other. If they don’t, don’t pay the DAG complexity tax. Question 8 — Failure handling and retries Options to decide on: Retry scope. Per statement, per child notebook, per master run, none. Retry counts. Per layer? Per table? Per environment? Backoff. Fixed, linear, exponential. Failure semantics. Fail-fast (stop on first failure) or best-effort (continue and report at the end). When to pick which: A good default for most projects: process-level retry (master retries the failed child), exponential backoff, per-layer max retry count, fail-fast within a child. Question 9 — Observability: how much do you log? Decide what every run captures: Execution status, start/end timestamps, duration Row counts per activity (source read, staging write, target write) MERGE metrics (inserted, updated, deleted) Watermark used and watermark captured Retry attempts Error message (truncated) Options for storage: Logs in source-side metadata DB (e.g., Azure SQL). Easy to query with SQL, integrates with monitoring tools. Logs in a Delta table in the lakehouse. Native to Databricks, queryable with Spark. Logs in both. Source-side for ops dashboards, Delta for analytics on the pipeline itself. When to pick which: Whatever you pick, make count validation a first-class output. The moment counts mismatch, you want to know — not three reports later. Question 10 — Schema evolution policy The cheapest decision to defer and the most painful one to retrofit. Decide which changes are allowed automatically: Where to enforce: At Bronze ingestion — fail loudly if source schema changes in a disallowed way At Silver — handle by transformation; new Bronze columns don’t auto-flow to Silver At Gold — strict contracts; consumers depend on the shape The contract changes per layer reflects the audience. Bronze is forgiving (data engineers see issues); Gold is strict (consumers can’t tolerate surprises). Question 11 — Idempotency and replay Can you re-run yesterday’s load and get the same result? Options: Idempotent by run_id. Re-running the same run_id is a no-op or produces identical output. Idempotent by data. Re-running with the same source data produces identical output (regardless of run_id). Non-idempotent. Replays may produce different results (e.g., timestamps based on current_timestamp()). Recommendation: aim for data-idempotent in every layer. Concretely: Staging: overwrite-per-run → idempotent by construction. Bronze: keyed MERGE → idempotent. Silver: pure transformation of Bronze inputs → idempotent. Gold: pure transformation of Silver inputs → idempotent. If you can’t replay a layer cleanly, that’s a design bug worth fixing early. Question 12 — Environment topology How many environments? How do they differ? Common patterns: Dev / Test/ Stage / Prod, separate workspaces and data. Per-developer dev, shared Test/Stage, isolated Prod. What changes between environments (drive these from config): Source connection strings Target storage paths / catalog names Retry counts (often higher in prod) Parallelism (often lower in dev to save cost) Logging verbosity Data masking rules Keep code identical across environments. Differences live in environment-scoped config (dev.yml, test.yml, stage.yml, prod.yml) loaded at runtime. Putting it together — three example shapes The same framework, three different projects, three different shapes: Shape A — Small marketing analytics project 15 tables, single source, weekly batch No staging — source is reliable, volumes small Bronze: lightly cleaned — analysts query it directly Silver: full ownership including light history and aggregations (no separate Gold needed) Gold: optional, only for the executive dashboard Code-per-table, sequential orchestration, fail-fast, minimal logging Shape B — Mid-size enterprise data platform 80 tables, 5 source systems, daily batch with some hourly Staging as transient table for Delta Loads Bronze: lightly cleaned + audit columns Silver: business entities (Customer, Policy, Claim), DAG orchestration Gold: split into Reporting + History zones Hybrid metadata-driven (generic ingestion, custom transforms), per-layer retry, structured count logs Shape C — Large multi-tenant Lakehouse 500+ tables, 20+ source systems, mixed batch/streaming Staging zone with file-level checkpoints (Auto Loader) Bronze: strictly raw + a parallel Bronze-Curated layer for cleansed views Silver: shared canonical model, narrow scope Gold: per-consumer zones with independent SLAs Fully metadata-driven, DAG everywhere, multi-store logging, strict schema contracts Notice none of these are “wrong.” They’re calibrated to the project. A short checklist for your own framework Before writing code, write down your answers to: Do we need a Staging layer? Why? How clean is Bronze? What’s allowed and what’s not? What does Silver own? Where does it stop? Is Gold one zone or multiple? How are they divided? Which load patterns do we support? Per table or universal? How metadata-driven? Where do exceptions live? What’s the orchestration shape per layer? What’s our retry and failure policy per layer? What does every run log? Where? What’s our schema evolution policy per layer? Are all layer's data-idempotent? What changes per environment, and what stays the same? If you have an answer for each, you have a framework design. If you skip any, you have a framework that will surprise you in production. Closing thought The medallion architecture isn’t a prescription — it’s a vocabulary. Bronze, Silver, Gold give you words to describe responsibilities. The actual responsibilities are yours to assign, based on what your project actually needs. Tweak deliberately. Document your tweaks. And revisit them when the project’s requirements change — because they will.
