8. WebSockets vs SSE vs Polling: Building Real-Time APIs | System Design Interview

Is your server crashing because clients are constantly asking, "Are there any new updates yet?" Traditional HTTP polling is a massive waste of server resources! Welcome back to Coding Vibes. In Episode 8 of our Top 50 Backend Scenario-Based Questions, we tackle a classic system design interview question: "A client needs real-time updates instead of polling. What would you use?" Whether you are building a live chat application, a stock market ticker, or real-time sports scores, choosing the right communication protocol is critical. In this video, I break down the exact technologies backend engineers use to push data to the client instantly, eliminating unnecessary API calls and reducing server load. What we cover in this video: • The Problem with Polling: Why Short Polling and Long Polling drain your CPU and network bandwidth. • WebSockets (Full-Duplex): How to establish a persistent, two-way connection for real-time apps using Node.js and Socket.io. • Server-Sent Events (SSE): The lightweight, built-in browser alternative when you only need one-way data streams (Server to Client). • System Design Trade-offs: When to choose WebSockets vs. SSE vs. GraphQL Subscriptions based on your specific use case. • Scaling Real-Time Servers: How to scale WebSockets across multiple backend instances using Redis Pub/Sub and load balancers. If you are preparing for a senior backend developer interview, understanding real-time architecture is an absolute game-changer. 👍 If this video helped you understand real-time backend systems, please hit the LIKE button and SUBSCRIBE to Coding Vibes! 👇 Which technology do you prefer for real-time features: WebSockets or Server-Sent Events? Let me know in the comments below! WebSockets vs Polling, Server-Sent Events SSE, Real-Time API, System Design Interview, Backend Developer Interview Questions, Node.js WebSockets, Socket.io Tutorial, Redis Pub Sub, Scaling WebSockets, How to build real-time chat, GraphQL Subscriptions, Software Engineering, Backend Architecture, Tech Interview Prep, Coding Vibes, Avinash Kumbhar. #WebSockets #SystemDesign #BackendDevelopment #CodingVibes #NodeJS #RealTimeAPI #SoftwareEngineering #TechInterview #Microservices #WebArchitecture #DeveloperLife