Building with AI → see the builds
My story
Eight years scaling products. Now I build my own.
I have spent my career taking products from small to large. At LINE I launched OpenChat in Japan and ran the experiments that scaled it past 3M monthly users. At Kakao Pay Securities I built the systems that brought dormant users back and moved $165M in trading volume. I ran my own consultancy, Valuelab, and took a YC-backed startup into the Japanese market from zero. Most recently, as a product manager on the AI Transformation team at Channel Corp, I built the company's small-business AI freemium business and converted its first paying customer.
Scale is also why I write. I co-authored a book on U.S. stock investing for Korean readers in their twenties — 60K+ readers across Korea and Taiwan, twenty printings over six years. Making a hard subject plain enough that a beginner acts on it is the same problem as product: you are not simplifying the thing, you are removing what stands between the person and the thing.
I am now a first-year MBA at Berkeley Haas, and I have started building myself. Eight years of scaling products taught me what makes something grow. Building with AI is how I put that to work on my own ideas — the work is below.