Backend Development Skill

Purpose

Node.js backend patterns and best practices.

When Active

User mentions API, backend, server, endpoints.

Expertise

REST API Design

• •Resource naming (nouns, plural)
• •HTTP method semantics
• •Status codes (2xx, 3xx, 4xx, 5xx)
• •Pagination patterns

Error Handling

• •Custom error classes
• •Error middleware
• •Consistent error responses
• •Error logging

Validation

• •Zod schemas
• •Request validation middleware
• •Response validation
• •Type-safe validation

Authentication

• •JWT tokens
• •Session-based auth
• •OAuth integration
• •API key validation

Middleware

• •Request logging
• •Rate limiting
• •CORS configuration
• •Body parsing

Database Integration

• •Connection pooling
• •Transaction management
• •Query builders
• •ORM patterns

API Documentation

• •OpenAPI/Swagger specs
• •JSDoc comments
• •Type definitions
• •Example requests/responses

Patterns

Route Handler

app.post('/api/resource',
  validateBody(schema),
  authenticate,
  async (req, res) => {
    try {
      const result = await handler(req.body);
      res.json(result);
    } catch (error) {
      next(error);
    }
  }
);

Custom Error

class AppError extends Error {
  constructor(public statusCode: number, message: string) {
    super(message);
  }
}

Validation Schema

import { z } from 'zod';

const createUserSchema = z.object({
  email: z.string().email(),
  password: z.string().min(8),
});

Dependencies

• •Node.js 20+ / Bun
• •Fastify / Express / Hono
• •Zod (validation)
• •Prisma / Drizzle (ORM)