Christian Yongwhan Lim

I studied math and computer science at Stanford, did my master’s in computer vision with Fei-Fei Li, and started a PhD at MIT with Asu Ozdaglar before leaving for industry: six years at Google, where I led Kick Start; a stretch at Two Sigma; and startups since — first as VP of Engineering at Arklex, now as Chief Architect at Probook, where we build AI voice agents for home service businesses.

Competitive programming has been the constant through all of it. I competed for Stanford, helped coach MIT’s team during my PhD, and coach Columbia’s today — two World Finals so far. Along the way the volunteer work turned into real jobs: I teach Columbia’s competitive programming courses, run the ICPC Foundation’s internship program, chair its symposium, help edit its journal, and still solve problems myself. Josh Alman and I are writing a book about the craft.

If you’re working on real-time AI, competitive programming, or computer science education — or you’re a student figuring out your next step — write to me at yongwhan@yongwhan.io. I read everything.