Chanjoong (CJ) Kim

idea to shipped, on a short clock.

• shipping 26 mini-apps in 30 days as an official partner on Toss, Korea’s fintech super-app, now 28 live. ~16K combined users. (top 3: 5.2K / 4.0K / 3.6K).’26
• reflect, a session-level metacognition harness for Claude Code. ~96% L1 cache hit-rate, ≤50 ms hook exit, ~$0.01 per warm reflection. picked into Anthropic’s Built with Opus 4.7 hackathon — 1 of 500 from 20,000+ applicants. MIT-licensed on npm.’26
• Oneline, type a sentence, get a working tool on your phone in ~2 min. three parallel agents behind a 3-layer judge. built solo at the Google I/O hackathon.’26
• neverboringnow, my solo studio. an AI audience-research tool that reports calibrated uncertainty per question (Wilson + Rubin + ICC), not just a single number.’26
• microgpt-efficiency, one decoder-only transformer across four backends (scalar / NumPy / PyTorch / CUDA), all landing on identical loss. backward passes derived by hand, checked against finite differences. 251× NumPy over scalar.’25

currently in the KMU Global PBL Program, Irvine, learning from engineers at OpenAI, AWS, and Blizzard.