Async/Await Under the Hood

Why async/await Exists

Promises improved callbacks, but chaining can still become hard to read. Async/await provides a synchronous-looking syntax over promise-based code.

Basic Example

async function getData() {
  const result = await fetchData();
  console.log(result);
}

What await Really Does

The await keyword pauses the async function until the promise resolves, but it does not block the event loop.

Parallel Execution

Sequential awaits can slow your code:

const a = await getA();
const b = await getB();

Better approach:

const [a, b] = await Promise.all([getA(), getB()]);

Production Insight

Async/await improves readability, but misuse (like sequential awaits) can reduce performance.