What problem does it solve? Server-side code often accumulates business logic in HTTP handlers, hides N+1 query problems, leaks database errors to clients, and relies on in-process queues or caches that break under real deployment conditions. This Skill provides concrete patterns and a review checklist for writing and reviewing the code that lives between request parsing and response shaping. ## Core Features & Use Cases - Layering guidance: Keeps handlers thin by splitting logic into service and repository layers only when a second caller or testability justifies it. - Query and transaction discipline: Covers avoiding SELECT *, detecting N+1 patterns, indexing filtered columns, and keeping network calls out of transactions. - Operational patterns: Addresses cache invalidation, durable idempotent background jobs, domain-to-HTTP error mapping, per-resource authorization, structured logging, and shared-store rate limiting. - Use Case: While reviewing a list endpoint that loads related records in a loop, apply the N+1 batching pattern and verify indexes with EXPLAIN before shipping. ## Quick Start Ask the assistant to review your endpoint handler and data access code using the backend-patterns checklist for layering, queries, caching, and error handling.
