NestJS: Build a Real-Time Social Media API (/w WebSockets) | Udemy

You may have heard the phrase: “To build a chat app, you need WebSockets.” But have you ever stopped to ask — why?

In this hands-on course, you’ll learn to build a real-time social media API using NestJS and WebSockets (Socket IO) — not just by memorizing syntax, but by understanding the fundamentals behind real-time communication. We’ll explore how sockets work under the hood, how data flows between client and server, and how to architect a system that can scale and respond instantly.

Rather than spoon-feeding you code, this course teaches you how to read documentation, think critically, and apply these skills to your own projects. You’ll gain the confidence to build and extend real-time features independently.

We start with a deep dive into the fundamentals of WebSockets, from how the TCP handshake works to the HTTP upgrade process that opens a persistent WebSocket connection. You’ll clearly understand what’s happening behind the scenes before writing a single line of code.

Next, you’ll build a simple chat app using raw WebSocket APIs, giving you a solid foundation before introducing any libraries. Once you understand the basics, we’ll transition into Socket IO, where you’ll explore its core concepts including custom events, rooms, and namespaces — and how they simplify real-time communication.

Once your WebSocket knowledge is solid, we shift gears and jump into NestJS fundamentals. You’ll learn about modules, controllers, services, and guards — and then apply them to build a complete, real-time social media backend

Why This Course?

This is not just another crash course. It’s a practical, project-driven guide that helps you think like a backend engineer. If you’re comfortable with JavaScript/TypeScript, have some Node.js or NestJS experience, and want to level up your backend skills with real-time architecture, this course is for you.

By the end, you’ll walk away with a complete real-time backend — ready to power your own chat app, live feed, or social platform.