Node.js — From Zero to Production

Understand what Node.js is, how it differs from browser JavaScript, and why it was created. Learn about the V8 engine and the role of libuv.

Learn how Node.js achieves concurrency with a single thread by understanding the event loop, its phases, microtasks, and how I/O is handled without blocking.

Understand CommonJS require/module.exports and ES Modules import/export, how module resolution works, and when to use each system.

Learn how to use npm to install, manage, and publish packages. Understand package.json, semver, lock files, and the node_modules resolution algorithm.

Read, write, and manipulate files and directories using the fs module. Use the path module to handle cross-platform file paths safely.

Understand the observer pattern in Node.js through the EventEmitter class — how to emit, listen for, and manage custom events.

Learn how Node.js handles large data efficiently through readable, writable, duplex, and transform streams, plus how Buffers represent binary data.

Run external commands with child_process and offload CPU-intensive work to worker threads without blocking the event loop.

Understand setTimeout, setInterval, setImmediate, process.nextTick, and key globals like __dirname, __filename, and the process object.

Understand the callback convention in Node.js, the error-first pattern, and why callback-based code can become hard to manage.

Learn how Promises represent eventual values, chaining with .then/.catch, and utilities like Promise.all, Promise.race, and Promise.allSettled.

Write asynchronous code that reads like synchronous code using async/await, and learn structured error handling with try/catch in async contexts.

Explore patterns like async iterators, AbortController for cancellation, concurrency limiting, and graceful shutdown strategies.

Build a basic HTTP server from scratch using Node's built-in http module. Understand requests, responses, status codes, and headers.

Learn the most popular Node.js web framework: routing, middleware, request/response helpers, and structuring an Express application.

Design clean REST APIs following best practices for resource naming, HTTP methods, status codes, pagination, filtering, and versioning.

Validate incoming data with libraries like Zod or Joi, and build consistent error responses with centralized error-handling middleware.

Implement user authentication with JWTs, sessions, and OAuth. Understand authorization patterns like role-based access control.

Connect to SQL (PostgreSQL, SQLite) and NoSQL (MongoDB) databases from Node.js. Understand connection pooling and query patterns.

Use tools like Prisma, Drizzle, or Knex to interact with databases through type-safe, higher-level abstractions instead of raw SQL.

Use Redis for in-memory caching, session storage, and rate limiting. Understand cache invalidation strategies and when caching helps.

Write unit tests for your Node.js code using a modern test runner. Learn assertions, mocking, spying, and test organization.

Test your HTTP endpoints end-to-end with supertest or similar tools. Ensure your routes, middleware, and database interactions work together.

Set up ESLint and Prettier to enforce consistent code style and catch common mistakes automatically.

Manage secrets and environment-specific settings with environment variables, .env files, and config libraries. Understand the twelve-factor app approach.

Add structured logging with pino or winston, and understand how to monitor Node.js apps with health checks and metrics.

Protect your app from common vulnerabilities: injection attacks, CSRF, XSS, rate limiting, helmet headers, and dependency auditing.

Containerize a Node.js app with Docker, write efficient Dockerfiles, and deploy to cloud platforms like Fly.io, Railway, or AWS.

Profile and optimize Node.js apps using clustering, load balancing, memory leak detection, and understanding V8 garbage collection.