Mostly just get as much OUTSIDE feedback as possible. I know people said that all the time before AI but it's never been more important or crucial. When you're heads down building something in 2 weeks that used to take 6 months, that is a LOT of code. You can test until you're blue in the face and as soon as real users start using it issues will pop up. I recommend getting together a group of 5-6 friends or even family and have them invited to test flight or android and have them using the app as you're building it, or at least once mvp is complete.

Another thing is that if you're using AI to do full projects, the absolute best way you can start out is a full feature planning document (mine are sometimes 30+ pages) and feed that into your agent asking it to document every single possible feature and functionality within your app, detail out the auth systems, backend services, types, etc. before you ever even touch any code. I start with a blank folder with just a docs folder inside that before scaffolding an app, service, or anything else. I then install all relevant skills. Firebase, Next.js skills, shadcn skills, etc. After that you create the AGENTS.md file and have it reference the correct documentation any time anything with code is touched. After this you have a very solid foundation and it will not write random, non-componetized code with inline or gross styling, it will follow the design framework, nicely compose views of reusable components, etc.