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name: backend-development description: Comprehensive backend development skill for building scalable backend systems using Python (FastAPI), Postgres, Redis, and more. Includes API design, database optimization, security implementation, and performance tuning.

Backend Development

This skill provides expert guidance for building robust, scalable, and secure backend systems, primarily focusing on the Python/FastAPI ecosystem used in this project.

Core Capabilities

1. API Design & Implementation

• RESTful Design: Resource-oriented URLs, proper HTTP methods, and status codes.
• FastAPI Best Practices: Validation with Pydantic, dependency injection, and async handlers.
• Documentation: Automatic OpenAPI generation, clear descriptions, and examples.

2. Database Management

• Schema Design: Normalized relationships, indexing strategies, and migration management (Alembic).
• ORM Usage: SQLAlchemy async session management, repository pattern.
• Optimization: N+1 problem avoidance, query analysis, connection pooling.

3. Security

• Authentication: JWT/OAuth2 implementation, password hashing (bcrypt/argon2).
• Authorization: Role-Based Access Control (RBAC), scopes.
• Data Protection: Input sanitization, SQL injection prevention (via ORM), secure headers.

4. Performance Tuning

• Caching: Redis implementation for specific endpoints or data.
• Async I/O: Non-blocking database and API calls.
• Background Tasks: Offloading heavy processing (Celery/Cloud Tasks).

Design Patterns

• Repository Pattern: Decouple business logic from data access.
• Dependency Injection: Manage dependencies (DB sessions, config) cleanly.
• Service Layer: Encapsulate complex business rules.

When to Use

• Designing new API endpoints or microservices.
• Optimizing slow database queries.
• Implementing complex business logic.
• Reviewing backend code for security and performance.
• Setting up authentication and authorization flows.