How Great Engineers Make Architectural Decisions — ADRs, Trade-offs, and an ATAM-Lite Checklist
Why Decision-Making Matters Without a shared framework, context fades and teams' re-debate old choices. ADRs solve that by recording the why behind design decisions — what problem we solved, what options we considered, and what trade-offs we accepted. A good ADR: Lives next to the code in your repo. Explains reasoning in plain language. Survives personnel changes and version history. Think of it as your team’s engineering memory. The Five Pillars of Trade-offs At Microsoft, we frame every major design discussion using the Azure Well-Architected pillars: Reliability – Will the system recover gracefully from failures? Performance Efficiency – Can it meet latency and throughput targets? Cost Optimization – Are we using resources efficiently? Security – Are we minimizing blast radius and exposure? Operational Excellence – Can we deploy, monitor, and fix quickly? No decision optimizes all five. Great engineers make conscious trade-offs — and document them. A Practical Decision Flow Step What to Do Output 1. Frame It Clarify the problem, constraints, and quality goals (SLOs, cost caps). Problem statement 2. List Options Identify 2-4 realistic approaches. Options list 3. Score Trade-offs Use a Decision Matrix to rate options (1–5) against pillars. Table of scores 4. ATAM-Lite Review List scenarios, identify sensitivity points (small changes with big impact) and risks. Risk notes 5. Record It as an ADR Capture everything in one markdown doc beside the code. ADR file Example: Adding a Read-Through Cache Decision: Add a Redis cache in front of Cosmos DB to reduce read latency. Context: Average P95 latency from DB is 80 ms; target is < 15 ms. Options: A) Query DB directly B) Add read-through cache using Redis Trade-offs Performance: + Massive improvement in read speed. Cost: + Fewer RU/s on Cosmos DB. Reliability: − Risk of stale data if cache invalidation fails. Operational: + Added complexity for monitoring and TTLs. Templates You Can Re-use ADR Template # ADR-001: Add Read-through Cache in Front of Cosmos DB Status: Accepted Date: 2025-10-21 Context: High read latency; P95 = 80ms, target <15ms Options: A) Direct DB reads B) Redis cache for hot keys ✅ Decision: Adopt Redis cache for performance and cost optimization. Consequences: - Improved read latency and reduced RU/s cost - Risk of data staleness during cache invalidation - Added operational complexity Links: PR#3421, Design Doc #204, Azure Monitor dashboard Decision Matrix Example Pillar Weight Option A Option B Notes Reliability 5 3 4 Redis clustering handles failover Performance 4 2 5 In-memory reads Cost 3 4 5 Reduced RU/s Security 4 4 4 Same auth posture Operational Excellence 3 4 3 More moving parts Weighted total = Σ(weight × score) → best overall score wins. Team Guidelines Create a /docs/adr folder in each repo. One ADR per significant change; supersede old ones instead of editing history. Link ADRs in design reviews and PRs. Revisit when constraints change (incidents, new SLOs, cost shifts). Publish insights as follow-up blogs to grow shared knowledge. Why It Works This practice connects the theory of trade-offs with Microsoft’s engineering culture of reliability and transparency. It improves onboarding, enables faster design reviews, and builds a traceable record of engineering evolution. Join the Conversation Have you tried ADRs or other decision frameworks in your projects? Share your experience in the comments or link to your own public templates — let’s make architectural reasoning part of our shared language.How Azure NetApp Files Object REST API powers Azure and ISV Data and AI services – on YOUR data
This article introduces the Azure NetApp Files Object REST API, a transformative solution for enterprises seeking seamless, real-time integration between their data and Azure's advanced analytics and AI services. By enabling direct, secure access to enterprise data—without costly transfers or duplication—the Object REST API accelerates innovation, streamlines workflows, and enhances operational efficiency. With S3-compatible object storage support, it empowers organizations to make faster, data-driven decisions while maintaining compliance and data security. Discover how this new capability unlocks business potential and drives a new era of productivity in the cloud.
