Use Promise.all() for Parallel Async Operations

Problem

Sequential await calls waste time when operations could run in parallel.

Solution

Use Promise.all() to execute multiple async operations simultaneously.

Benefit

Can reduce execution time by 70% for independent async operations.

Code Example

// Sequential (slow): 3 seconds total
const user = await fetchUser();
const posts = await fetchPosts();
const comments = await fetchComments();

// Parallel (fast): 1 second total
const [user, posts, comments] = await Promise.all([
    fetchUser(),
    fetchPosts(),
    fetchComments()
]);