What problem does it solve? Building scalable server-side applications requires consistent patterns for API design, database access, caching, and error handling, and this Skill provides proven TypeScript implementations so you avoid reinventing fragile solutions. ## Core Features & Use Cases - API & Layering Patterns: RESTful route design, repository pattern, service layer separation, and middleware composition for Next.js API routes. - Database & Caching: Query optimization, N+1 prevention, Supabase transactions, Redis cache-aside, and cached repository decorators. - Resilience & Security: Centralized error handling, retry with exponential backoff, JWT authentication, role-based access control, rate limiting, job queues, and structured logging. - Use Case: When building a Next.js API that queries Supabase, apply the repository pattern with Redis caching and JWT middleware to get a maintainable, performant endpoint without designing the architecture from scratch. ## Quick Start Ask the assistant to apply backend patterns to design a cached, authenticated Next.js API route backed by Supabase.