About

I'm Arvin, a full-stack engineer with 15 years of experience. I've built steady income through remote.work, with occasional freelance projects via fengqihetai.com.

In 2025 I started moving into App Store tool apps. My first product, OOTD Diary, landed its first paying user within 30 days of launch — proof the direction works.

This site records my experiments, revenue data, and the mistakes along the way. Not tutorials — a real-time build log.