How to stop your Lovable prototype from turning into a mess after day 5?

Last weekend I tried Lovable to build a simple habit tracker, and the starting results were mind-blowing. But by Thursday, every small tweak started breaking existing features I wasn't even working on. Prompts became exhausting, and my patience was tested.

I started attaching a small constraint document: a brief summary of the app's goals, explicit restrictions on what it shouldn't alter, and a record of all error-free screens. I paste this right at the start of every big prompt.

It’s far from perfect, but it reduced unexpected code breakages significantly.

Do you paste guidelines with your prompts, or do you rely on starting from scratch each time?