I Built an “Online but Not Replying” System… And It Created Trust Issues 😭

You’ve seen this. They are Online You send a message … … No reply. Still online. 👉 Now you’re thinking: Are they busy? Ignoring you? Or is the system wrong? So I turned this into a coding challenge. And honestly… it exposed a real bug. 😂 The Problem The logic looks simple: User opens app → set Online User leaves → set Offline That’s it. But real systems don’t behave that cleanly. ⚠️ What Goes Wrong? In real-world apps: • User closes the app suddenly • Network disconnect is not detected • “Offl