Fastapi Patterns

A solid reference for structuring production FastAPI services around dependency injection and explicit layers. You get patterns for app factories with lifespan hooks, separate Pydantic schemas for create/update/response, async database sessions, OAuth2 token dependencies, and test fixtures that override dependencies instead of hitting real resources. The security checklist covers the basics (Argon2, JWT validation, CORS credentials). Useful when you're reviewing a FastAPI PR and want concrete examples of where routers, schemas, and CRUD logic should live, or when you're tired of seeing password hashes leak into response models because someone skipped the response_model declaration.