tomevault-io Backend Development Guidelines (Node.js / Express / TypeScript)
This skill collects reusable backend patterns for services built with Node.js, Express, and TypeScript.
Purpose
- Establish a consistent structure for backend services.
- Reduce bugs by separating concerns (routing vs business logic vs data access).
- Make failures observable (error tracking + structured logs).
- Make changes testable (clear boundaries, predictable inputs/outputs).
When to Use
Use this skill when working on:
- Routes / controllers / request handlers
- Service-layer business logic
- Repository/data-access patterns (e.g., Prisma)
- Middleware (auth, validation, error boundaries)
- Configuration management
- Monitoring/error tracking and performance spans
- Testing and refactoring backend code
Quick Start
New endpoint checklist
- Route: defines HTTP method + path + middleware only
- Controller: parses input, validates, calls service, formats response
- Service: implements business logic; no HTTP knowledge
- Repository: encapsulates DB access and query construction (when non-trivial)
- Validation: schema-validated inputs (e.g., Zod)
- Monitoring: capture exceptions and add key spans
- Tests: unit tests for service/repo; integration tests for route
New service checklist
-
src/config/centralized config loading/validation -
src/middleware/includes auth + request context + error boundary -
src/routes/delegates to controllers -
src/controllers/follows a consistent error-handling pattern - Monitoring is initialized early in process startup
Core principles (high signal)
- Routes only route (no business logic in routes)
- Controllers handle HTTP, services handle business rules
- Validate all external inputs (params/body/query)
- Centralize configuration (avoid scattered
process.envaccess in app code) - Capture and contextualize errors (monitoring + structured logs)
- Repositories for complex DB access (avoid scattered queries)
- Test at the right layer (fast unit tests + targeted integration tests)
Related Skills
| Need to… | Skill |
|---|---|
| Understand layered architecture | architecture-overview |
| Build routes + controllers | routing-and-controllers |
| Structure services + repositories | services-and-repositories |
| Validate inputs | validation-patterns |
| Add monitoring / error tracking | sentry-and-monitoring |
| Create middleware | middleware-guide |
| Database access patterns | database-patterns |
| Configuration patterns | configuration |
| Async + error patterns | async-and-errors |
| Testing strategy | testing-guide |
| End-to-end examples | complete-examples |
Source: willyu1007/AI_First_Template — distributed by TomeVault.