Key architectural differences between AWS and Azure explained

Introduction

In today’s fast-moving digital world, cloud platforms are the foundation of everything from small startups to global enterprises. Choosing the right one can make all the difference when it comes to scalability, security, and driving innovation. With over 94% of companies relying on cloud services, expanding from AWS to Microsoft Azure unlocks a host of new possibilities.

Azure not only provides robust tools and services to optimize your infrastructure, but it also puts you at the forefront of AI advancements. From integrated AI services like Azure OpenAI to sophisticated machine learning models, Azure empowers businesses to transform how they build, deploy, and scale intelligent applications. This guide explores the key differences between AWS and Azure—covering network architecture, availability zones, security, and more—helping you make informed decisions to future-proof your cloud strategy and stay ahead in an AI-driven world.

1. Network architecture: AWS VPC vs. Azure VNET

AWS Virtual Private Cloud (VPC)

In AWS, the Virtual Private Cloud (VPC) is the backbone of your network architecture. It lets you build isolated environments where you control every aspect of your networking. The subnets in a VPC must be clearly designated as either public or private, ensuring a firm boundary between internet-facing resources and internal systems. Here's how AWS VPC handles traffic and segmentation:

AWS VPC Network Segmentation

Key components:

• Public Subnet: Hosts internet-facing resources, such as web servers, which handle incoming HTTP traffic through an Internet Gateway (IGW).
• Private Subnet: Hosts internal resources like databases that don’t have direct internet access.
• Internet Gateway (IGW): The bridge that provides internet access for public subnets.
• VPC Endpoint Gateway: Allows secure, private access to AWS services like S3 and DynamoDB without needing an internet connection.
• NAT Gateway: Enables outbound internet traffic from private subnets.
• Security Groups and Network ACLs: Provide both stateful and stateless traffic filtering to control inbound and outbound traffic.

Architectural characteristics:

• Explicit Segmentation: Subnets are clearly marked as public or private, making it easy to manage resource placement.
• Manual Configuration: Setting up Internet Gateway (IGW), NAT Gateway, and route tables requires hands-on configuration.
• Availability Zones (AZs): Resources are often spread across multiple AZs to ensure high availability and fault tolerance.

Azure Virtual Network (VNet)

Azure Virtual Network (VNet) provides similar network isolation as AWS, but with a stronger focus on managed services and simplifying network segmentation. It’s designed to reduce the complexity of manual configuration and make networking more efficient.

Azure VNET Network Segmentation

Key components:

• Public Subnet: Hosts resources that have direct internet access through assigned public IP addresses.
• Private Subnet: Holds internal resources and securely connects to Azure services using Private Endpoints through Private Link.
• Network Security Groups (NSGs): Control traffic to and from both public and private subnets, ensuring your resources are properly shielded.
• Azure NAT Gateway: Offers outbound internet connectivity for resources that don't have public IPs.
• Service Endpoints and Private Links: Enable secure, private access to Azure services without needing to expose your resources to the internet.

Architectural characteristics:

• Streamlined internet acess: Public IP addresses can be directly assigned to resources, bypassing the need for an Internet Gateway (IGW). Azure’s NAT Gateway provides outbound internet connectivity for private subnets, offering a simpler setup compared to AWS’s NAT Gateway.
• Azure NAT Gateway: Offers outbound connectivity for private subnets without public IPs. The setup is simpler compared to AWS’s NAT Gateway, reducing the need for intricate routing configurations.
• Integrated services: Azure emphasizes managed services like Private Link, which simplify complex networking tasks, reducing the need for hands-on management.
• Abstraction: Less manual configuration of routing and network appliances, making it easier for organizations to manage.

Key architectural differences:

•   Internet connectivity:

• AWS: Requires an Internet Gateway (IGW) for public subnet internet access.
• Azure: Public IPs are directly assigned; no IGW equivalent is needed, and Azure NAT Gateway abstracts much of the internet connectivity configuration.

• Subnet designation:

• AWS: Subnets must be explicitly marked as public or private.
• Azure: Subnets are neutral; traffic control is handled by NSGs and public IP assignment.

• Network segmentation:

• AWS: Provides granular control using Security Groups and NACLs.
• Azure: Simplifies this with NSGs and Application Security Groups (ASGs), offering easier management of security rules.

2. Availability zones and redundancy

AWS Availability Zones

In AWS, regions are divided into multiple Availability Zones (AZs) to ensure high availability and fault tolerance. Resources can be deployed across these AZs, but it’s not automatic—you need to explicitly distribute them for redundancy, which often involves manual setup.

Multi-AZ architecture ensures redundancy and fault tolerance.

Architectural approach:

• Manual distribution: Resources must be manually deployed across AZs to achieve redundancy.
• Load balancing: AWS uses Elastic Load Balancers to distribute traffic across multiple AZs for high availability.
• High Availability Configurations: For services like RDS, configuring multi-AZ deployments requires additional setup to ensure proper redundancy and failover.

Azure Availability Zones

Azure also provides Availability Zones but takes a different approach by offering automatic zone-redundancy for many services. This abstraction reduces the complexity of managing high availability, especially for managed services. However, it’s important to remember that certain IaaS services, like Azure VMs, still require explicit configuration for redundancy across AZs. Additionally, geo-redundancy (multi-region failover) isn’t automatic for every service and must be configured for mission-critical workloads.

Azure abstracts zone management for many services. It’s zone redundant by default without manual configuration

Architectural approach:

• Automatic redundancy: Many managed services, like Azure SQL Database, come with built-in zone redundancy by default, saving you the hassle of manual configuration.
• Managed services: Azure abstracts most of the complexity by automatically handling replication and failover for services like Azure SQL Database.
• Zone-aware services: Not all services in Azure require explicit AZ configurations, making it easier to achieve high availability without manual effort.

Key architectural differences:

•  Resource deployment:

• AWS: Requires manual placement across AZs for redundancy.
• Azure: Many services are inherently zone-redundant, though not all services are automatically redundant.

• Operational overhead:

• AWS: Achieving high availability often requires more manual configuration.
• Azure: Reduces complexity with built-in redundancy for managed services, such as Azure SQL Database, allowing for easier scaling and high availability without additional setup.

3. Security models: AWS vs. Azure Controls

AWS Security Controls

In AWS, security is managed with a combination of Security Groups (SGs) and Network ACLs (NACLs). Security Groups operate at the instance level, while NACLs control traffic at the subnet level, offering multiple layers of security.

AWS uses SGs for instance-level security and NACLs for subnet-level control.

Key points:

• Security Groups: Manage inbound and outbound traffic by attaching to instances. Since they are stateful, they automatically allow return traffic without the need for additional rules.
• Network ACLs: Control traffic at the subnet level and are stateless, meaning both inbound and outbound rules must be defined.

Architectural implications:

• Layered security: By combining SGs for instance-level control and NACLs for subnet-level control, AWS provides a granular approach to managing traffic.
• Complexity: The trade-off is complexity, as you need to manage both SGs and NACLs separately, which can add overhead when configuring security across large deployments.

Azure Security Controls

Azure takes a more streamlined approach to security with Network Security Groups (NSGs) and Application Security Groups (ASGs), making it easier to manage security policies across your infrastructure. Unlike AWS, Azure simplifies the process by combining functionality, reducing the need to manage multiple layers.

Azure simplifies security management through NSGs and ASGs, integrating directly with VMs or network interfaces

Key points:

• NSGs: Control inbound and outbound traffic at both the VM and subnet levels, similar to AWS SGs. Like AWS SGs, NSGs are stateful and automatically allow return traffic.
• Flexible application: NSGs can be applied to subnets, individual VMs, or network interfaces.
• ASGs: Offer centralized security rules for logical groupings of VMs, making it easier to manage policies for specific sets of resources.
• Dynamic security policies: Security rules can reference ASGs, reducing the need to manually update IP addresses whenever new instances are added.

Architectural implications:

• Simplified management: With NSGs handling both instance-level and subnet-level security, Azure eliminates the need for a separate layer like NACLs, streamlining your security setup.
• Efficient policy application: ASGs make it easier to apply consistent security policies across groups of VMs without needing to reconfigure individual resources.

Key architectural differences:

•  Security layers:

• AWS: Uses both SGs (stateful) and NACLs (stateless) for security, which can lead to more granular control but requires more effort.
• Azure: Primarily uses NSGs (stateful), simplifying the model by not needing an additional layer like NACLs.

• Resource grouping:

• AWS: Lacks a direct equivalent to ASGs, though you can use EC2 tagging for dynamic grouping in some cases.
• Azure: ASGs allow for more efficient security management by applying centralized policies to logical groupings of VMs.

4. Managed services: Levels of automation

AWS Managed Services

AWS offers powerful managed services, but achieving high availability and scaling often requires manual setup. For example, if you want to configure RDS Multi-AZ deployments, you’ll need to manually set up replication across Availability Zones to ensure redundancy.

 

AWS services provide a high level of control but require more configuration for high availability.

Key services:

• RDS Multi-AZ: Requires manual configuration to enable replication across AZs for high availability.
• EC2 Auto Scaling: Involves setting up scaling rules to automatically adjust resources based on demand.
• Elastic Load Balancer (ELB): Distributes incoming traffic across AZs but requires additional setup.

Architectural characteristics:

• Customization: AWS gives you full control over configurations, allowing you to tailor setups to your needs.
• Operational responsibility: With more control comes more responsibility—there’s a greater need for hands-on management to ensure high availability and scaling.

Azure Managed Services

Azure takes a different approach by emphasizing automation and built-in redundancy in its managed services. Services like Azure SQL Database and Cosmos DB come with high availability baked in, so you spend less time configuring infrastructure and more time focusing on your core business. However, even though Azure automates much of the infrastructure management, careful planning for failover is still essential, particularly for mission-critical workloads.

Azure services are more abstracted, automating key operational tasks like scaling and availability across zones.

Key services:

• Azure SQL Database: Automatically manages replication, backups, zone redundancy, and scaling without manual intervention.
• Azure App Service: Provides a fully managed PaaS solution for web applications, with built-in autoscaling and minimal configuration required.
• Azure Cosmos DB: Delivers global replication with automatic scaling, making it easy to build globally distributed applications.

Architectural characteristics:

• Built-in high availability: Services are designed with resilience in mind, ensuring high availability without additional configuration.
• Reduced operational overhead: By automating critical tasks like redundancy and scaling, Azure reduces the need for manual maintenance, allowing you to focus on innovation instead of infrastructure management.

Key architectural differences:

• Control vs. Convenience:

• AWS: Offers more control but requires manual configurations to achieve redundancy and scaling, especially across AZs.
• Azure: Automates much of the redundancy and scaling, particularly for managed services, with minimal user intervention required.

5. Storage resiliency and data replication

AWS Storage Options

AWS offers a range of storage tiers, each designed for different durability and cost requirements. For instance, S3 Standard replicates data across multiple facilities in a region, providing high durability by default, while S3 One Zone-IA offers a more cost-effective option by storing data in a single Availability Zone (AZ), though this comes with lower durability.

Key characteristics:

• S3 Standard: Automatically replicates data across multiple facilities within a region for high durability.
• S3 One Zone-IA: Stores data in a single AZ, reducing cost but sacrificing some resiliency.

Architectural characteristics:

• Automatic replication: By default, S3 provides high durability across multiple AZs, ensuring data redundancy.
• Choice of redundancy: AWS offers a range of storage classes to allow flexibility in cost and durability, letting users balance redundancy with budget.

Azure Storage Options

Azure gives users more granular control over data replication, offering several replication strategies depending on your needs. Whether you require local, zonal, or geo-redundancy, Azure provides storage options that ensure data availability and resilience.

Key characteristics:

• Locally Redundant Storage (LRS): Keeps three copies of your data within a single data center, ensuring protection against local hardware failures.
• Zone-Redundant Storage (ZRS): Replicates data synchronously across three AZs for higher availability.
• Geo-Redundant Storage (GRS): Replicates data asynchronously to a secondary region, providing protection against regional failures.
• Geo-Zone-Redundant Storage (GZRS): Combines ZRS and GRS for maximum resilience by replicating both within and across regions.

Architectural characteristics:

• Customization: Azure provides multiple levels of control over data replication, letting you choose the redundancy model that best suits your business needs.
• Disaster recovery: Azure includes built-in options for cross-regional replication, giving you out-of-the-box disaster recovery capabilities.

Key architectural differences:

• Replication control:
• AWS: Automatic multi-AZ replication with fewer options for customization.
• Azure: Offers a wider range of replication strategies, including local, zonal, and geo-redundancy, for greater flexibility.
• Disaster recovery planning:
• AWS: Cross-region replication requires additional services and setup.
• Azure: Provides built-in geo-redundancy options for simpler disaster recovery planning.

6. Private Connectivity to Cloud Services

AWS VPC Endpoints

In AWS, VPC Endpoints allow you to connect privately to AWS services without exposing your resources to the internet. However, setting up these endpoints requires manual configuration for each service, making it a more hands-on process.

Types:

• Gateway Endpoints: Used for services like S3 and DynamoDB.
• Interface Endpoints: Powered by AWS PrivateLink to connect to other AWS services.

Architectural characteristics:

• Manual setup: Each service you want to connect privately to requires its own endpoint, meaning more manual work.
• Service-specific endpoints: The type of endpoint you need depends on the service, with different setups for gateway versus interface endpoints.

Azure Private Link and Endpoints

Azure streamlines private connectivity with Private Link and Private Endpoints, offering a more unified approach to accessing both Azure services and your own services securely. This reduces the complexity compared to AWS and makes managing private connections more efficient.

Features:

• Private Endpoints: These are network interfaces that allow you to privately and securely connect to a service through Azure Private Link.
• Service Integration: Works seamlessly with Azure services and can also be used for your own custom applications, creating a more versatile connection model.

Architectural characteristics:

• Simplified configuration: With a more unified setup, it’s easier to manage and configure private connections in Azure.
• Unified approach: Azure uses the same method—Private Link—to connect to various services, making the process much more consistent and straightforward compared to AWS.

Key architectural differences:

• Configuration complexity:
• AWS: Requires different setups depending on the type of service, with separate configurations for gateway and interface endpoints.
• Azure: Simplifies this with Private Link, providing a unified approach for connecting to multiple services.
• Service accessibility:
• AWS: Each service requires a specific endpoint type, which can lead to more management overhead.
• Azure: Private Link offers broader access with fewer configurations, making it more user-friendly.

Conclusion

Understanding the key architectural differences between AWS and Azure is crucial for organizations looking to optimize their cloud strategy. While both platforms provide robust services, their approaches to network architecture, availability zones, security models, managed services, and storage resiliency vary significantly. By understanding these distinctions, businesses can fully leverage Azure’s capabilities while complementing their existing AWS expertise, creating a powerful multi-cloud strategy that boosts operational efficiency.

Key takeaways:

• Network architecture: AWS offers granular control over network segmentation, but Azure simplifies it with integrated managed services, reducing manual configuration.
• Availability Zones: Azure’s managed services come with built-in zone redundancy, while AWS often requires more manual intervention to achieve multi-AZ redundancy.
• Public internet access: AWS uses an Internet Gateway for public internet access, whereas Azure simplifies this by directly assigning public IPs to resources.
• Private subnet outbound traffic: Both platforms use NAT Gateways for outbound traffic, but Azure abstracts the configuration more, making it easier to manage.
• Security models: Azure streamlines security with NSGs and ASGs, offering simpler and more flexible traffic control than AWS’s combination of Security Groups and NACLs.
• Managed services: Azure automates critical tasks like redundancy and scaling, while AWS often requires manual configuration for high availability.
• Storage resiliency: Azure provides more granular replication options, while AWS relies on predefined storage tiers.
• Private endpoints: Azure’s Private Link and Endpoints offer a more seamless and integrated approach to private connectivity compared to AWS’s VPC Endpoints, which require more manual setup.

By adapting to these architectural differences, your organization can unlock Azure’s full potential, complementing your AWS expertise and creating a multi-cloud strategy that enhances availability, operational efficiency, and cost management.

Additional resources:
Azure Architecture Guide for AWS Professionals: For a detailed comparison and further reading on transitioning from AWS to Azure.

Mapping AWS IAM concepts to similar ones in Azure: For a direct mapping of AWS IAM concepts to Azure’s security solutions, read this detailed discussion.