I'm Joonwoo. I design products and then I build them.
Born and raised in Seoul. Cognitive science at UC San Diego, the design and interaction track, class of 2026. Moving to San Francisco in December.
I like products that tell people the truth about themselves. The step app I'm building refuses to round your numbers up, and the watch-later tool I built tells you why it filed a video where it did. That habit started in a cognitive science classroom and it is now how I decide what to build.
Two of my products are live right now, and if this site calls something live, it is.
How I work
- Figma
- Every screen starts here. Components, tokens, and the frame I sign off before any code.
- Claude Code
- Builds with me. I plan and design, it implements, I review the diff.
- Codex
- Reviews what Claude wrote, and implements plans of its own. Two models, two opinions, fewer bugs.
- SwiftUI and Xcode
- Walking to the Moon is native iOS: HealthKit, SwiftData, Firebase.
- Next.js, Supabase, Vercel
- Laterlist and this site.
- Astro
- Provecho's site, because a coffee roaster's website should load instantly.
- Framer
- Where the previous version of this portfolio lived, and still a fast way to ship a client page.
Off work
Music first. I listen to everything and I DJ; I ran marketing for the DJs and Vinylphiles club at UCSD. I take photos when I travel, which is often. I watch more esports than I should, League and Valorant mostly, and I still lift a few times a week.