Parallel awaits & error handling

Sequential await is a trap

await reads so naturally that it's easy to write it wrong. Two independent calls, one after another, run in series — the second doesn't even start until the first finishes. If each takes 100ms, you just spent 200ms doing what should take 100.

The tell: two awaits in a row where the second doesn't use the first's result. That's a signal they could run at the same time.