What a Worker actually is

What this is about

Your code runs per request inside a shared runtime. There is no box that is "yours" and no program of yours that stays alive between requests.

That is the whole film. Everything else is scaffolding for it.

The short version

Here’s something every vibe coder should know. When you deploy to Cloudflare Workers, you are not renting a computer. You are handing over code that runs only when someone asks for something.

There is no machine with your name on it. Your code lives inside a runtime that is already running, and a small isolated space for it is created the moment a request arrives.

That is not a virtual machine and it is not a container. Cloudflare calls it an isolate, and their own documentation says one starts about a hundred times faster than a program booting on a machine of its own.

Here is the part that surprises people. Between requests, nothing of yours is promised to still be running. An isolate can be shut down and thrown away at any point.

So a value you set once and expect to find later is a bug waiting to happen. Cloudflare’s own documentation warns against exactly that.

Here is the check. Ask your AI whether this Worker holds anything in memory between requests. Then ask where that thing should live instead.

And this is not a flaw to work around. The forgetting is the trade that buys the speed. When something does have to be remembered, the platform gives you places built for remembering.

A Worker is not a computer you rent. It is code that wakes up for one request, and may keep nothing at all afterwards.