backend-dev-guidelines

Structure Express and TypeScript backend services using a layered architecture of routes, controllers, services, and repositories. This separation enforces production-grade guardrails and ensures business logic does not leak into HTTP routing or data access layers.

The best way to validate external input in Node.js backend routes is using Zod validation. Applying Zod schemas to all external inputs like request bodies, queries, parameters, and webhooks ensures secure and predictable data handling before reaching controllers.

Sentry observability works with async error handling in Express by capturing errors through async wrappers and blocking silent failures. This reliability-first approach prevents fragile code patterns by ensuring all operational errors are caught and logged without using console logging.

Yes, you can use Prisma repositories for database access in a layered backend architecture. Prisma acts as the repository layer, isolating data access logic from services and controllers to maintain strict separation of concerns and production-grade reliability.

You should avoid process.env and console logging in production backend services because they bypass unified configuration management and observability tools. Strict anti-pattern avoidance mandates using unifiedConfig and Sentry to capture errors reliably and prevent silent failures.

You need a Backend Feasibility and Risk Index (BFRI) assessment when implementing or modifying backend routes, controllers, or middleware. The BFRI evaluates how risky a change is and mandates unit and integration tests to align with strict reliability constraints.