JavaScript Async/Await Pitfalls in Production

async/await improves readability, but it can hide subtle issues when API calls overlap and errors are swallowed. This article focuses on practical patterns that prevent production incidents.

Pitfall 1: Serial requests by accident

If independent calls are awaited one by one, total response time increases.

const user = await fetchUser();
const projects = await fetchProjects();

Run independent calls together:

const [user, projects] = await Promise.all([fetchUser(), fetchProjects()]);

Pitfall 2: Missing cancellation strategy

Without cancellation or staleness guards, older responses can override newer UI state.

let requestVersion = 0;

export async function loadDashboard() {
  const version = ++requestVersion;
  const data = await fetch("/api/dashboard").then((r) => r.json());

  if (version !== requestVersion) return null;
  return data;
}

Pitfall 3: Catch blocks that hide failures

Avoid empty catches because they make monitoring and debugging harder.

try {
  await saveChanges(payload);
} catch (error) {
  console.error("saveChanges failed", error);
  throw error;
}

Reliable async code is mostly about discipline: model concurrency intentionally, guard stale responses, and fail loudly when behavior is unexpected.