FastAPI Patterns provides structured guidelines and production-oriented code patterns for building, structuring, and reviewing FastAPI services. It covers creating application factories, separating Pydantic request and response schemas, setting up request-scoped dependencies, and writing asynchronous endpoints. Additionally, it provides guidance on custom error handling, OpenAPI configuration, database dependency overrides in tests, and maintaining security and performance checklists. Reach for it when you need reference implementations and best practices for developing reliable FastAPI applications.