I build AI systems that can prove the work got done.

The voice agents I work on book appointments, update records, and send messages. When a tool times out, the work may have succeeded even though the agent reports failure. I block the retry until the outside state is known.

Christian Yongwhan Lim
Chief architect and educator in New York

Where I work

Probook

Chief Architect

I decide what the agent may claim when the business system cannot confirm the result.

What I’m building →

ICPC Foundation

Director of Internships

I run internships where students take over planning, review, and delivery.

136 completed internships →

Columbia University

Adjunct

I teach students to derive, prove, and implement algorithms under contest constraints.

Courses and teaching →

Start where the system and the business record disagree.

Contest judging taught me to distrust a result that cannot survive an independent check.

I define what would make the caller’s job complete, then find the first fact the system cannot establish. Sometimes the outside system exposes too little state to know.

Then I narrow what the agent may promise. If nobody owns the uncertainty, I do not call the run complete.

Work someone else can inspect

These results are here because another person can check them.

Notes from the work

All writing

Bring me one disputed run.

I’ll tell you where I would inspect first. I am a poor fit when the expected answer is already fixed.

Describe the failure →