Advanced FastAPI Patterns

Master advanced FastAPI patterns including async programming, WebSockets, custom middleware, rate limiting, caching, and API versioning. Build production-ready APIs.

lessons: 10
level: advanced
time: 8 hours
price: free

Start with Async Endpoints & Concurrency →

What you'll learn

Understand the difference between def and async def in FastAPI
Know when to use sync vs async path operation functions
Use asyncio.sleep to simulate non-blocking async work
Grasp how the event loop handles concurrent requests
Use the lifespan context manager for app startup and shutdown logic
Create async dependencies that provide shared resources
Understand resource management with lifespan vs deprecated on_event
Build endpoints that consume async dependencies
Understand the WebSocket protocol and how it differs from HTTP
Create a WebSocket endpoint that accepts connections
Send and receive text messages over a WebSocket connection
Handle WebSocket disconnections gracefully

Lessons

Each lesson runs a real FastAPI server in the browser and grades your code against its own endpoints.

01
Async Endpoints & Concurrency
Understand the difference between sync and async endpoints in FastAPI, and learn when to use each for optimal performance.
Read the theory
02
Async Dependencies & Lifespan
Learn how to use async dependencies and the lifespan context manager to manage application startup and shutdown resources.
Read the theory
03
WebSocket Basics
Learn how to create WebSocket endpoints in FastAPI for real-time bidirectional communication between client and server.
Read the theory
04
WebSocket Rooms & Broadcasting
Learn the connection manager pattern to manage multiple WebSocket clients and broadcast messages to all connected users.
Read the theory
05
Custom Middleware & Request Processing
Learn how to build custom middleware in FastAPI to intercept and process requests and responses, adding headers, logging, and timing information.
Read the theory
06
Rate Limiting with Dependencies
Learn how to implement rate limiting using FastAPI's dependency injection system with in-memory request tracking.
Read the theory
07
Response Caching Patterns
Learn how to implement response caching using ETags and in-memory caches to improve API performance and reduce redundant processing.
Read the theory
08
Custom Response Types
Learn to use different response classes in FastAPI including HTMLResponse, JSONResponse with custom headers, and RedirectResponse.
Read the theory
09
Application Events & Startup Logic
Learn to use the lifespan context manager for application startup and shutdown logic, including resource initialization and cleanup.
Read the theory
10
API Versioning & Router Composition
Learn to version your API using APIRouter with prefixes and tags, composing multiple versioned routers into a single application.
Read the theory

What you'll learn

Lessons

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