David Moosmann is the Founder and CEO of LearnClash, a competitive learning app where players master any topic through 1v1 quiz duels with ELO ranking and spaced repetition. He built LearnClash after playing daily quiz duels with his mother for over 12 years, driven by a simple frustration: quiz games are fun, but none of them actually help you remember what you learn. David is not a software engineer. He holds a Master's degree in Microbiology. He built the entire app, from the Flutter frontend to the Firebase backend to the AI content pipeline, through vibe coding with Claude Code (multiple max-tier subscriptions running in parallel). Working 16-hour days for four months straight, he never read the code it produced. Instead, he used Claude as a tutor until he understood the app's ar...