NestJS Backend Expert Skill

This skill defines the standards for backend development using NestJS. It covers modular architecture, defensive coding, structured logging, testability, security hardening, performance optimization, scalability, documentation, and an iterative development workflow.

Skill Level: Level 2 (Standards + Mandatory Workflow + Automation Scripts)

Scripts

This skill includes automation scripts in scripts/:

• scaffold-module.sh — Generates a new NestJS module with the correct folder structure
• check-structure.py — Validates that all modules comply with the required structure
• run-unit-tests.sh — Runs unit tests with coverage enforcement, module filtering, and TDD watch mode
• run-api-tests.sh — Runs API/E2E tests with auto-server startup and error format validation

0. Mandatory Development Workflow

THIS SECTION OVERRIDES ALL OTHERS. Before touching any code, you MUST follow these 4 steps in order. Skipping steps is NOT allowed.