15. How Real-Time Communication Works in System Design | WebSockets, SSE, MQTT, WebRTC Explained
Real-Time Communication Protocols Explained | WebSockets, SSE, Long Polling, MQTT, WebRTC | System Design Interview Guide (FAANG Level)
In this video, we deep dive into Real-Time Communication (RTC) — one of the most important concepts in system design interviews, backend engineering, and building modern high-performance applications.
You will learn how real-time systems like WhatsApp, Google Docs, Stock Market Apps, Multiplayer Games, and Live Streaming Platforms actually work under the hood.
This video explains all real-time communication protocols with architecture diagrams, use cases, pros/cons, and interview-level clarity.
🔥 What You Will Learn
✔ What is Real-Time Communication?
✔ Why low latency matters in system design
✔ WebSocket deep dive (handshake, frames, full-duplex model)
✔ SSE (Server Sent Events) and when to use it
✔ Long Polling — still used today?
✔ MQTT protocol explained (for IoT)
✔ WebRTC — P2P video/audio data transfer
✔ Use cases: Chat apps, stock updates, gaming, dashboards
✔ Real-Time Architecture patterns
✔ Scaling real-time systems (load balancing, sharding, partitions)
✔ How FAANG asks RTC questions in interviews
🎯 Best Use Cases
WhatsApp/Telegram messaging
Live dashboards & trading apps
Google Docs–style collaboration
Live video/audio communication
Real-time gaming
IoT sensor networks
🧠 Perfect For
✔ System Design Interviews (FAANG-level)
✔ Backend Developers
✔ Distributed System Engineers
✔ WebSocket / WebRTC Learners
✔ Anyone building real-time applications
🔍 Topic Covered
What is WebSocket in system design?
WebSocket vs SSE vs Long Polling
Real-time communication protocols explained
WebRTC explained
MQTT for IoT
Real-time system design interview
How chat apps work internally
Real-time architecture
FAANG system design preparation
Tags
#systemdesign #backenddevelopment #websockets #realtimecommunication #webrtc #mqtt #softwareengineering #faanginterview #systemdesigninterview #techtutorial