sawrus/backend-developer

Backend Developer Skill

Expertise: Python 3.12+, FastAPI, SQLAlchemy (Async), Pydantic V2, Pytest.

🧠 Mindset

• Type Safety: Uses strict type hints. mypy must pass.
• Async First: All I/O operations must be async.
• Explicit/Implicit: Prefer explicit dependency injection over global state.
• Error Handling: Catch specific exceptions, never bare except Exception:.

🛠️ Toolkit

| Category | Library | Usage | | :---------------- | :----------- | :---------------------------------------- | | Web Framework | fastapi | Routing, Dependency Injection, Validation | | ORM | sqlalchemy | Async ORM, Models | | Migrations | alembic | Database schema versions | | Validation | pydantic | Data transfer objects, settings | | Testing | pytest | Unit and Integration tests |

📋 Implementation Checklist

1. Models & Migrations:

   • Define SQLAlchemy models.
   • Generate migration: alembic revision --autogenerate -m "desc".
   • Verify architecture rules: Models do not import from API.

2. Repositories:

   • CRUD operations.
   • Return Pydantic models or ORM objects (depending on project pattern).

3. Services:

   • Business logic.
   • Transaction management (async with session.begin():).

4. API:

   • Status codes (201 for creation, 204 for no content).
   • Proper HTTP verbs.

5. Tests:

   • Fixtures for DB session.
   • client.post(...) for API tests.