Real-Time Systems (WebSockets, WebRTC): How to Build Applications That Work in Real Time — Course on asibiont.com

Hello, colleagues!

Today I want to talk about a topic that has been at the center of attention for developers around the world for several years now — real-time systems. If you've ever wondered how online chats, voice assistants like Siri, or collaborative editors like Google Docs work, then you're already familiar with this area. But let's dive into what lies behind these technologies and why the course "Real-Time Systems (WebSockets, WebRTC)" on asibiont.com could be your key to creating modern, responsive applications.

Why Are Real-Time Systems Important Right Now?

The world is moving toward instantaneity. Users are no longer willing to wait — not even a second. According to a Statista report for 2025, more than 70% of users expect web applications to respond to their actions in less than 2 seconds, and for chats and notifications, this threshold drops to milliseconds. Real-time technologies are not just a trendy fad but a necessity for any product that wants to be competitive.

Take, for example, financial exchanges: a delay of 100 milliseconds can cost millions of dollars. Or online education: imagine listening to a lecture while the instructor sees your reaction with a delay — it destroys engagement. Real-time systems solve these problems by ensuring synchronous data transmission between hundreds and thousands of clients.

What Are Real-Time Systems and How Do They Work?

A real-time system is software that processes data and provides a result within a strictly defined time interval. In the context of web development, this means that information is transmitted from server to client (and back) almost instantly, without the need for constant page refreshes.

The main protocols and technologies underlying them include:

• WebSockets: a bidirectional communication channel between client and server. Unlike regular HTTP, where the client sends a request and waits for a response, WebSockets allow the server to send data to the client independently. This is the foundation for chats, notifications, and stock quotes.
• Server-Sent Events (SSE): a simplified alternative for unidirectional data transmission from server to client. Ideal for live news feeds or status updates.
• WebRTC: a technology for transmitting audio, video, and data in real time between browsers without intermediate servers. Zoom, Google Meet, and voice assistants are built on it.

But this is just the tip of the iceberg. To build reliable real-time applications, you need to understand:
- CRDT (Conflict-free Replicated Data Types) and OT (Operational Transformation): algorithms that allow multiple users to edit a single document simultaneously without conflicts. They are the foundation of Google Docs.
- Pub/Sub (Publish-Subscribe): an architectural pattern where senders (publishers) are not tied to receivers (subscribers). It is implemented through message brokers like Redis, NATS, or Kafka.
- Scaling and Security: how to handle thousands of simultaneous connections without losing performance and protect data from interception.

What Will You Learn in the Course "Real-Time Systems (WebSockets, WebRTC)"?

The course on asibiont.com is designed for developers who want to move from simple REST APIs to full-fledged real-time applications. The program covers all key aspects: from the basics of WebSockets to building production solutions using Redis and Kafka.

Here are just a few topics we will cover in detail:

1. WebSockets and SSE: how to establish a connection, handle errors, maintain heartbeat to prevent disconnections.
2. WebRTC: setting up peer-to-peer connections, transmitting audio and video, working with STUN/TURN servers. You will learn how to create your own voice assistant.
3. Collaboration Algorithms: CRDT and OT — how to avoid conflicts during simultaneous editing.
4. Pub/Sub Systems: comparison of Redis, NATS, and Kafka — when to use what, how to set up reliable message delivery.
5. Scaling: how to distribute load across servers, use horizontal scaling, and databases for real-time data.
6. Security: encrypting WebSocket connections, protecting against CSRF, authentication in real-time applications.

Each topic is backed by practical code examples. You don't just read theory — you write working applications that can be run immediately.

Who Is This Course For?

The course is aimed at developers who are already familiar with the basics of web programming (JavaScript, Node.js, or Python) and want to delve into the real-time direction. It is suitable for:

• Backend developers who want to master the architecture of real-time systems.
• Frontend developers striving to create interactive interfaces with live updates.
• Fullstack engineers who want a holistic understanding of real-time data transmission.
• Students and beginners who want to stand out in the job market — skills in WebSockets and WebRTC are among the top 10 most in-demand according to LinkedIn for 2026.

If you've ever thought, "How do I make a chat that doesn't lag?" or "How do I implement a video call in the browser?" — this course is for you.

How Learning Works on asibiont.com: AI Personalization

Now for the most interesting part — how we teach. On asibiont.com, we use artificial intelligence to generate personalized lessons for each student. This is not just video lectures or static texts — the neural network analyzes your current knowledge level, goals, and learning pace to create a program that perfectly suits you.

Here's how it works:

1. Initial Testing: you answer a few questions about your experience and goals. The neural network determines which topics you should start with.
2. Lesson Generation: based on your answers, AI creates text lessons (yes, we have no videos — only structured text that is easier to perceive and faster to review). Each lesson includes theory explanations, code examples, and a practical assignment.
3. Adaptation in Process: if you quickly mastered WebSockets but got stuck on WebRTC, the neural network will adjust the program — give more exercises on the difficult topic and fewer on the familiar one.
4. Simple Language Explanations: complex concepts like CRDT or OT are broken down into understandable steps with metaphors and visualizations (in text format).
5. 24/7 Access: you learn at your own pace, anytime. No deadlines or fixed schedules.

Why is this effective? A study published in the journal "Computers & Education" in 2024 showed that personalized learning using AI improves material retention by 30-40% compared to traditional methods. The neural network doesn't just provide information — it adapts it to your cognitive style. If you understand better through examples, AI will give more cases. If through diagrams, it will add logical flowcharts.

Additionally, the text format allows you to quickly return to previously covered material. No need to rewind videos — just find the desired section in the text. This saves time and reduces cognitive load.

Practical Example: How to Create a Simple Chat with WebSockets

To give you an idea of what learning looks like in practice, let's break down a small example. Imagine you want to create a chat where messages arrive instantly. Without AI personalization, you would start with protocol theory, but the neural network, knowing you are already familiar with HTTP, will suggest jumping straight to code.

Here's what a minimal server looks like in Node.js using the ws library:

const WebSocket = require('ws');
const wss = new WebSocket.Server({ port: 8080 });

wss.on('connection', (ws) => {
  console.log('New client connected');

  ws.on('message', (message) => {
    console.log(`Received: ${message}`);
    // Send the message to all connected clients
    wss.clients.forEach((client) => {
      if (client.readyState === WebSocket.OPEN) {
        client.send(message);
      }
    });
  });

  ws.on('close', () => {
    console.log('Client disconnected');
  });
});

On the client side (in the browser), we connect:

const socket = new WebSocket('ws://localhost:8080');

socket.onopen = () => {
  console.log('Connection established');
  socket.send('Hello, server!');
};

socket.onmessage = (event) => {
  console.log(`Message from server: ${event.data}`);
};

This is the basics. In the course, we will go further: add error handling, heartbeat to maintain the connection, authentication, and scaling via Redis. You will learn to write code that withstands thousands of simultaneous connections.

What Will You Get as a Result?

After completing the course, you will be able to:

• Independently design and implement real-time applications of any complexity — from chats to voice assistants.
• Choose the right technologies for the task: when to use WebSockets and when WebRTC.
• Work with message brokers (Redis, NATS, Kafka) to build reliable Pub/Sub systems.
• Understand collaboration algorithms and implement them in your projects.
• Scale real-time applications from dozens to millions of users.

And all this — with AI support that adapts the program to you.

Start Learning Right Now

Real-time systems are not the future; they are the present. Every day, millions of people use applications that work in real time without even noticing it. But behind the scenes, there are complex algorithms and protocols that we will break down in the course.

Don't put it off until tomorrow — start today. Go to the course page Real-Time Systems (WebSockets, WebRTC) and get access to a personalized program created by AI specifically for you. Learn at your own pace, experiment with code, and create applications that work instantly.

See you on asibiont.com!