What problem does it solve? Choosing the right Python framework, async strategy, and project structure is error-prone when developers default to familiar tools instead of context-driven decisions. This Skill provides decision frameworks and principles for Python architecture so you pick FastAPI, Django, or Flask based on actual requirements rather than habit. ## Core Features & Use Cases - Framework Selection Guidance: Decision trees and comparison tables for FastAPI, Django, and Flask based on project type, async needs, and admin requirements. - Async vs Sync Strategy: Rules for choosing async def versus def, plus async library selection (httpx, asyncpg, aiofiles) and the I/O-bound versus CPU-bound golden rule. - Type Hints and Validation: Patterns for typing function signatures, generics, and when to use Pydantic for runtime validation. - Project Structure and Testing: Layout principles for small scripts through large applications, background task selection (Celery, ARQ, BackgroundTasks), error handling, and pytest async testing patterns. - Use Case: You are starting a new microservices API and are unsure whether to use Django or FastAPI, whether endpoints should be async, and how to structure the codebase. This Skill walks you through the decision checklist to reach a justified architecture. ## Quick Start Ask the assistant to help you choose between FastAPI and Django for a new API project and recommend an async strategy and project structure.