| 1 | --- |
| 2 | title: Promise.all() for Independent Operations |
| 3 | impact: CRITICAL |
| 4 | impactDescription: 2-10× improvement |
| 5 | tags: async, parallelization, promises, waterfalls |
| 6 | --- |
| 7 | |
| 8 | ## Promise.all() for Independent Operations |
| 9 | |
| 10 | When async operations have no interdependencies, execute them concurrently using `Promise.all()`. |
| 11 | |
| 12 | **Incorrect (sequential execution, 3 round trips):** |
| 13 | |
| 14 | ```typescript |
| 15 | const user = await fetchUser() |
| 16 | const posts = await fetchPosts() |
| 17 | const comments = await fetchComments() |
| 18 | ``` |
| 19 | |
| 20 | **Correct (parallel execution, 1 round trip):** |
| 21 | |
| 22 | ```typescript |
| 23 | const [user, posts, comments] = await Promise.all([ |
| 24 | fetchUser(), |
| 25 | fetchPosts(), |
| 26 | fetchComments() |
| 27 | ]) |
| 28 | ``` |
| 29 |