kp-launch-vs-async

One-line summary

launch is fire-and-forget — it returns a Job you don't usually await. async is parallel computation — it returns a Deferred<T> whose .await() gives you the result. Use launch for side effects; use async for parallel decomposition where you need every result.

When to use this skill

• Starting concurrent work and unsure which builder to pick.
• Code that returns Job where it should return Deferred<T>, or vice versa.
• Code review wants to know "is this async actually being used for parallel decomposition, or is it a mis-applied launch?".

When NOT to use this skill

• Sequential, non-concurrent work — no builder needed; just call the suspend function.
• Switching to a different dispatcher for a single call — use withContext, not launch or async.

Core content

launch — fire-and-forget side effects.