Missing awaits and slow APIs
Async/Await Mistakes
Learn the async/await mistakes behind early success messages, slow endpoints, broken loops, and swallowed promise failures.
await pauses only the current async function. Missing await lets later code continue early, while sequential awaits can make independent work unnecessarily slow.
Most common symptoms
Success UI appears before saving, tests finish too early, loops log done before work finishes, and APIs wait for independent calls one by one.
What to practice
Compare missing await, async forEach, sequential await, and Promise.all. Each case shows the output order and the safer fixed pattern.
Production fix direction
Await real dependencies, return promise chains, use Promise.all for independent work, and choose for...of when sequential behavior is intentional.
Practice this topic
Start with the strongest case, then continue through related examples.
missing await
Without `await`, code keeps going while the promise is pending.
async forEach issue
Use `for...of` for sequential work or `Promise.all(items.map(...))` for parallel work.
sequential await
Sequential awaits are correct for dependencies but slow for independent API calls.
parallel Promise.all
This pattern reduces latency for independent dashboard or page data.
Missing return
Missing returns commonly break request chains and test setup.