Python Backend Expert

When to Use

Activate this skill when:

• Creating or modifying FastAPI route handlers (endpoints)
• Defining or updating Pydantic v2 request/response schemas
• Writing SQLAlchemy 2.0 async models, queries, or relationships
• Implementing the repository pattern for data access
• Writing service layer business logic
• Creating or running Alembic migrations
• Setting up dependency injection chains with Depends()
• Handling errors across the route/service/repository layers