I built a 126K-line Android app with AI — here is the workflow that actually works

Most developers trying AI coding tools hit the same wall. They open a chat, type "build me a todo app," get something that looks right, and then spend 3 hours fixing the mess. They try again with a bigger project and it falls apart faster. They conclude AI coding is overhyped. I had the same experience. Then I changed my approach — not the tool, the process around it. Over 4 months I built How Are You?! , a safety-critical Android app that monitors elderly people living alone. 126,000 lines of Kotlin. 144 versions. 130 test files. 3 languages. Solo developer with zero Kotlin experience when I started. The entire codebase was AI-generated — I never wrote Kotlin manually. This article is not about the app. It is about the workflow that made this possible. Why most people fail with AI coding Two reasons: Expectations are wrong. People expect to describe a feature in plain English and get production code. That works for a function. It does not work for a system. AI is not a replacement for