Most Next.js tutorials cover the happy path — a request comes in, the server responds quickly, done. But what happens when the task takes 15 seconds? Server functions time out. Users get errors. The experience breaks.
Here's the pattern that solves it, used in production for any long-running server-side task.
Why Standard API Routes Break on Long Tasks
Next.js API routes (and serverless functions generally) have execution time limits. On Vercel's free tier, that's 10 seconds. Even on paid plans, holding a connection open for 30+ seconds is unreliable — networks drop, browsers time out, proxies intervene.
The naive approach:
