Iterating without breaking what works

Once part of your app works, protect it. Scope every follow-up prompt to the area you are changing — name the page, the component, the flow — and explicitly say what must stay untouched. Review changes after each iteration, not after ten. When the agent shows you what it modified, skim the list: if it touched files unrelated to your request, ask why before piling on the next feature. Keep a working checkpoint you can return to. Whether that is a git commit or your tool's version history, "roll back and re-prompt" is often faster than untangling a bad change with more prompts.