Node.js

Node.js is a JavaScript runtime built on Chrome's V8 engine that enables running JavaScript outside the browser. It's the foundation of modern JavaScript tooling and a popular choice for building servers, APIs, and CLI tools.

Key Features

• Event-driven: Non-blocking I/O for high concurrency
• Single-threaded: Event loop handles async operations
• npm ecosystem: Access to millions of packages
• V8 engine: Fast JavaScript execution
• Cross-platform: Runs on Windows, macOS, Linux

Common Use Cases

• Web servers: Express, Fastify, Koa, Hapi
• REST APIs: Backend for web and mobile apps
• GraphQL: Apollo Server, Mercurius
• Real-time apps: WebSocket servers with Socket.io
• CLI tools: Build scripts, developer tools
• Serverless: AWS Lambda, Vercel, Cloudflare Workers

Simple HTTP Server

const http = require('http');

const server = http.createServer((req, res) => {
  res.writeHead(200, { 'Content-Type': 'application/json' });
  res.end(JSON.stringify({ message: 'Hello, World!' }));
});

server.listen(3000, () => {
  console.log('Server running on port 3000');
});

Popular Frameworks

Framework	Style	Best For
Express	Minimal	General purpose, most popular
Fastify	Performance	High-throughput APIs
NestJS	Opinionated	Enterprise, Angular-like
Koa	Modern	Express successor, cleaner async
Hapi	Configuration	Enterprise, plugins

What We Like

• JavaScript everywhere: Same language frontend and backend
• Developer productivity: Fast development cycles
• Performance: Excellent for I/O-bound workloads
• Ecosystem: Package for nearly anything
• Community: Active development and support

What We Don't Like

• CPU-bound work: Single thread struggles with computation
• Callback patterns: Legacy code can be messy (promises/async help)
• Dependency management: Security and bloat concerns
• Type safety: Requires TypeScript for robustness

Best Practices

1. Use TypeScript: Catch errors early, improve maintainability
2. Handle errors properly: Uncaught exceptions crash the process
3. Use environment variables: Never commit secrets
4. Validate input: Use Joi, Zod, or similar
5. Monitor your app: APM, logging, health checks