What is Azure Application Architecture Guide

The cloud is changing the way applications are designed. Instead of monoliths, applications are decomposed into smaller, decentralized services. 

These services communicate through APIs or by using asynchronous messaging or eventing. Applications scale horizontally, adding new instances as demand requires.

These trends bring new challenges. Application state is distributed. Operations are done in parallel and asynchronously. The system as a whole must be resilient when failures occur. Deployments must be automated and predictable. 

Monitoring and telemetry are critical for gaining insight into the system. The Azure Application Architecture Guide is designed to help you navigate these changes.

Traditional on-premises	Modern cloud
Monolithic, centralized Design for predictable scalability Relational database Strong consistency Serial and synchronized processing Design to avoid failures (MTBF) Occasional big updates Manual management Snowflake servers	Decomposed, de-centralized Design for elastic scale Polyglot persistence (mix of storage technologies) Eventual consistency Parallel and asynchronous processing Design for failure (MTTR) Frequent small updates Automated self-management Immutable infrastructure

This guide is intended for application architects, developers, and operations teams. It's not a how-to guide for using individual Azure services. After reading this guide, you will understand the architectural patterns and best practices to apply when building on the Azure cloud platform.

How this guide is structured

The Azure Application Architecture Guide is organized as a series of steps, from the architecture and design to implementation. For each step, there is supporting guidance that will help you with the design of your application architecture.

Architecture styles

The first decision point is the most fundamental. What kind of architecture are you building? It might be a microservices architecture, a more traditional N-tier application, or a big data solution. We have identified several distinct architecture styles. There are benefits and challenges to each.

Learn more:

• Architecture styles

Technology choices

Two technology choices should be decided early on, because they affect the entire architecture. These are the choice of compute service and data stores. Compute refers to the hosting model for the computing resources that your applications runs on. Data stores includes databases but also storage for message queues, caches, logs, and anything else that an application might persist to storage.

Learn more:

• Choosing a compute service
• Choosing a data store

Design principles

We have identified ten high-level design principles that will make your application more scalable, resilient, and manageable. These design principles apply to any architecture styles. Throughout the design process, keep these ten high-level design principles in mind. Then consider the set of best practices for specific aspects of the architecture, such as auto-scaling, caching, data partitioning, API design, and others.

Learn more:

• Design principles

Quality pillars

A successful cloud application will focus on five pillars of software quality: Scalability, availability, resiliency, management, and security. Use our design review checklists to review your architecture according to these quality pillars.

• Quality pillars