Your Coroutines Work Locally. Then Production Happens. You wrote the async code. It's elegant, non-blocking, and runs beautifully on your machine. Then you deploy — and somewhere around 3 AM, Grafana wakes you up with a memory graph that looks like a ski slope. Welcome to Kotlin Coroutines in Production. This guide skips the Hello World phase entirely. It's about what happens when real load hits — thread starvation, silent memory leaks, and exception handlers that don't actually handle anything. The kind of bugs that only show up at scale and only at the worst possible time. Scopes, Supervisors, and Why the Wrong Choice Crashes Everything Most developers treat coroutineScope and supervisorScope as roughly the same thing. They are not. With coroutineScope, one failing child cancels the parent and every sibling — great for all-or-nothing operations, catastrophic for independent tasks. In production, supervisorScope is almost always the right call.…