AsyncIO in production: event loop, tasks, and the traps no one warns you about (opens in new tab)

You've shipped async code. It works in dev. Then production hits — and it hangs, leaks memory, or silently swallows exceptions. Here's what actually matters. The mental model most tutorials skip When you write async def and await, you're not getting parallelism — you're getting cooperative multitasking. The event loop runs one coroutine at a time. Every await is a voluntary yield: "I'm waiting for I/O, go run something else." This means: CPU-bound work blocks the entire loop — no other corout...