Stop Writing Async/Await Like This — The Hidden Performance Traps in JavaScript

Most JavaScript developers use async/await every day. It reads cleanly, it feels synchronous, and it removed the callback hell that made early Node.js code a nightmare to maintain. But there's a problem: async/await makes it dangerously easy to write sequential code when you actually want parallel execution. And most developers don't notice until something is embarrassingly slow in production. Let's dig into the traps, why they happen, and how to write async JavaScript that actually performs. The Classic Trap: Sequential Awaits Here's code that looks perfectly fine: async function getUserDashboard ( userId ) { const user = await fetchUser ( userId ); const posts = await fetchUserPosts ( userId ); const notifications = await fetchNotifications ( userId ); return { user , posts , notifications }; } Looks clean, right? Three awaits, three results. But here's what's actually happening: Fetch user — wait for it to finish Then fetch posts — wait for it to finish Then fetch notifications — wa