Things I have built or written outside of work.
A multi-agent orchestrator for coding agents.
Runs Claude Code, Codex and other coding agents from one board, assigns each task to the right agent and model by quota, cost, speed and quality, reuses warm context, and records what the work consumed.
A local, zero-knowledge tracker for airline, hotel and credit card reward balances.
Runs as a background service on your own computer and syncs point balances, membership tiers and certificate details from loyalty programs without sending credentials to the cloud: passwords are encrypted locally with a master password only you know.
Resources for church worship leaders, online since the early 2000s.
Guitar lessons, song sheets and the material behind the Worship Guitar Bible.
E-book search and loan management for Korean public libraries.
Searches the e-book catalogues of the Gyeonggi, Anyang and Gyeonggi Education digital libraries in one place, lets you bookmark titles, hide books and whole categories you are not interested in, and borrow with one click. Built for my own reading and released for anyone else’s. Django, Vue.js and Bootstrap.
Worship Guitar Bible for Worship Leaders · 유성환 · 예솔출판사
A twelve-lesson course that takes someone with no guitar experience to leading worship in four to five months. Written for people training to lead worship in churches and mission organizations.
Available from Godpeople, YES24, Interpark, Aladin, Kyobo Book Centre.