🚀 Realtime Communication in Frontend (Polling vs WebSocket vs SSE)

Realtime features are everywhere today — chat apps, delivery tracking, payments, notifications. But one mistake many developers make is: 👉 Using WebSocket for everything. In real production systems, we use a mix of: Polling Server-Sent Events (SSE) WebSocket 👉 The goal is simple: use the simplest solution that works reliably. 🧠 1. What is Realtime Communication? Realtime means: 👉 Data updates without refreshing the page But important point: 👉 Not all realtime needs to be instant Some features can tolerate delay (2–5 seconds), and that changes the design. 🔁 2. Polling (Simple but Powerful) What is Polling? Client keeps asking server for updates: setInterval(async () => { const res = await fetch("/status"); const data = await res.json(); console.log(data); }, 5000); When Polling Works Best Use polling when: Data changes slowly You need high reliability Simplicity is preferred Real Example: Payment Status Let’s understand this properly. Flow: User clicks “Pay” Redirected to third