What fifteen years in the ICPC changed about how I solve problems
Reflections across competing, coaching, judging, organizing, and teaching—and what those roles reveal about the real work of problem solving.
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Systems · People · Learning
Christian Yongwhan Lim
I build difficult systems, develop exceptional technical people, and create institutions that compound.
Chief Architect at Probook · Adjunct at Columbia · Director of Internships at the ICPC Foundation. Formerly Google Research and Two Sigma.
New York, 2026
Selected work
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A few things that define the body of work
01 / Systems
02 / People
03 / Institutions
Reliable AI voice agents
Architecture, evaluation, recovery, and the many boundaries between a convincing model and a dependable business system.
6 system boundaries · architecture field note Read the work →Columbia competitive programming
Courses, community, and World Finals teams—an environment for sustained technical growth.
429+ members · 14 course offerings · 2 World Finals teamsRead the work →ICPC internship program
A distributed technical-talent pipeline connecting students, mentors, and durable open projects.
136 completed · 14 active · searchable public recordRead the work →Working Notes
How I review an ICPC contest with a team
The scoreboard records outcomes. A useful review reconstructs the decisions, failure modes, and team interactions that produced them.
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