Async Parallel

## Promise.all() for Independent Operations When async operations have no interdependencies, execute them concurrently using `Promise.all()`. **Incorrect (sequential execution, 3 round trips):** ```typescript const user = await fetchUser() const posts = await fetchPosts() const comments = await fetchComments() ``` **Correct (parallel execution, 1 round trip):** ```typescript const [user, posts, comments] = await Promise.all([ fetchUser(), fetchPosts(), fetchComments() ]) ```