backend-dev-guidelines

Backend Dev Guidelines is an opinionated engineering-standards skill for building production Node.js, Express, TypeScript, and microservice backends. It frames Claude as a senior backend engineer working under strict architectural and reliability constraints, and its goal is predictable, observable, maintainable services. Rather than offering loose suggestions, it defines how backend code must be written: layered architecture, explicit error boundaries, strong typing and validation, centralized configuration, and first-class observability.

The skill leads with a Backend Feasibility & Risk Index (BFRI) — a scoring rubric across architectural fit, business-logic complexity, data risk, operational risk, and testability — used to decide whether to proceed, add tests and monitoring, refactor, or redesign before coding. Its core doctrine mandates a Routes to Controllers to Services to Repositories to Database flow with no layer skipping, routes that contain zero business logic, controllers that extend a shared BaseController for response and error handling, all errors routed to Sentry, a single unifiedConfig source instead of raw process.env access, and Zod validation of all external input. A set of resource files expands on routing and controllers, services and repositories, async and error handling, middleware, database patterns with Prisma, validation, configuration, testing, monitoring, architecture overview, and complete worked examples.

It is aimed at backend engineers and teams standardizing service code, and at Claude when working on routes, controllers, services, repositories, Express middleware, Prisma access, Zod validation, Sentry integration, or backend refactors and migrations. The frontmatter carries a 'risk: critical' tag from its source repo, but the content itself is conventional, defensive architectural guidance with example TypeScript code and no risky operations.