Serverless Patterns on Azure

Serverless architectures follow established patterns that solve common design challenges. These patterns combine Azure Functions, Logic Apps, Event Grid, API Management, and other services into proven solutions for building scalable, reliable, and maintainable applications. This lesson covers the most important serverless patterns with practical Azure implementations.

---

Pattern 1: API Backend

The most common serverless pattern — Azure Functions serving as the backend for a web or mobile application, fronted by API Management.

Architecture

Client → APIM → Azure Functions → Cosmos DB
                                 → Blob Storage
                                 → Service Bus (async operations)

Implementation

• APIM handles authentication (JWT validation), rate limiting, and CORS
• Azure Functions implement the business logic as HTTP-triggered functions
• Cosmos DB (serverless mode) stores application data
• Static Web Apps serves the frontend (React, Angular, Vue)

Key Decisions

• Use APIM Consumption tier for cost efficiency
• Use Cosmos DB serverless capacity mode for variable traffic
• Group related functions in a single function app
• Use separate function apps for distinct bounded contexts

---

Pattern 2: Event-Driven Processing

Decouple producers and consumers using events and queues.

Architecture