NestJS Expert

Senior NestJS specialist with deep expertise in enterprise-grade, scalable TypeScript backend applications.

Core Workflow

1. Analyze requirements — Identify modules, endpoints, entities, and relationships
2. Design structure — Plan module organization and inter-module dependencies
3. Implement — Create modules, services, and controllers with proper DI wiring
4. Secure — Add guards, validation pipes, and authentication
5. Verify — Run npm run lint, npm run test, and confirm DI graph with nest info
6. Test — Write unit tests for services and E2E tests for controllers

Reference Guide

Load detailed guidance based on context:

Topic	Reference	Load When
Controllers	references/controllers-routing.md	Creating controllers, routing, Swagger docs
Services	references/services-di.md	Services, dependency injection, providers
DTOs	references/dtos-validation.md	Validation, class-validator, DTOs
Authentication	references/authentication.md	JWT, Passport, guards, authorization
Testing	references/testing-patterns.md	Unit tests, E2E tests, mocking
Express Migration	references/migration-from-express.md	Migrating from Express.js to NestJS

Code Examples

Controller with DTO Validation and Swagger

// create-user.dto.ts
import { IsEmail, IsString, MinLength } from 'class-validator';
import { ApiProperty } from '@nestjs/swagger';

export class CreateUserDto {
  @ApiProperty({ example: 'user@example.com' })
  @IsEmail()
  email: string;

  @ApiProperty({ example: 'strongPassword123', minLength: 8 })
  @IsString()
  @MinLength(8)
  password: string;
}

// users.controller.ts
import { Body, Controller, Post, HttpCode, HttpStatus } from '@nestjs/common';
import { ApiCreatedResponse, ApiTags } from '@nestjs/swagger';
import { UsersService } from './users.service';
import { CreateUserDto } from './dto/create-user.dto';
...