senior-backend

Guides backend system development with Node.js, Express, Go, Python, PostgreSQL, GraphQL, and REST APIs. Use when the user says: 'design an API', 'optimize database queries', 'implement authentication', 'set up backend', 'create API endpoint', 'database migration', 'fix N+1 query', 'add rate limiting', 'backend code review'. Covers API scaffolding, database optimization, security implementation, and performance tuning. Do NOT use for frontend/UI work (use senior-fullstack), test writing (use tdd-workflow), or changelog generation.