You deployed it, it worked, and now it is off again. This is frustrating in a specific way when you did not write the code yourself, because the usual advice assumes you can read a stack trace. You mostly do not need to.
Four causes cover almost everything. You can tell them apart by when it stops, without opening the code at all.
It stops after a quiet period
Fifteen minutes, half an hour, an hour. Some consistent stretch of nothing happening, then it is gone, and it comes back the moment you interact with it.
That is a sleep policy on a free tier, not a fault. The host suspends projects that look idle to save money, and an app waiting for events looks exactly like an idle project. No code change fixes this. You need a host that does not sleep, which generally means a paid tier somewhere.
It stops when you close your laptop
Then it never left your laptop. Running it in a terminal, or in the preview pane of an editor, means the project lives as long as that window does. Deploying is the step that moves it somewhere else; a preview is not a deploy.
This one is common with AI editors specifically, because the run button makes it feel deployed. It is running, just on your machine.
It stops under load, then comes back
Works fine, gets busy, dies, restarts, works fine. That is running out of memory. Something is accumulating: caching everything it sees, keeping a growing list, or opening a browser it never closes.
Two fixes, both easy: move to a tier with more memory, or paste the relevant file into your AI and ask what is being kept in memory that does not need to be. It is usually one line.
It stops at random with no pattern
That is a crash, and it means an error nobody handled. In Node, a failed promise with no catch will take the whole process down; in Python, an uncaught exception does the same.
What matters here is less the cause than the response: the project should restart itself. Crashes are normal in anything long-running. A host that brings it back automatically turns a crash into a blip, and one that does not turns it into your evening.
How to actually find out
Read the logs. They are less intimidating than they look. You want the last few lines before it stopped, and the first few lines after it tried to start again. The reason is almost always in one of those two places, in English.
Then paste them into whichever AI built the project. Logs are exactly the kind of input a model is good with, and "here is what my app printed before it died" is a far better prompt than "it broke".
| WHEN IT STOPS | WHAT IT IS |
|---|---|
| After a quiet stretch | Host sleep policy |
| When you close your laptop | It was never deployed |
| When it gets busy | Out of memory |
| At random | Unhandled crash |
| Right after every deploy | Missing environment variable |
The setup that stops this happening
Somewhere that does not sleep, restarts on crash, and keeps logs you can read. That is the whole checklist. On Spocket all three are the default, and a project that crash-loops stops being retried and tells you, rather than pretending to be up.