A lab for small, finished things.
Each project gets built, shipped, and written up. Here’s what’s on the bench — and the log of how it got made.
LIVEPuzzle Lab
A logic-puzzle workshop built on a from-scratch solver that reasons the way a person does — so every generated puzzle is solvable without guessing.
- Sudoku
- Killer
- Calc
LIVEBellTab
A school bell schedule countdown that lives in the browser tab title — the time remaining is readable from the tab strip, the taskbar, or a projector across the room.
- Countdown
- Schedules
- Big mode
From the lab
Read the build log →What broke building a bell clock
Forty-three bugs in ten days, almost none of them typos. The mistakes were beliefs — that a comment was true, that a stub stood in for a browser, that a green test meant what its name said. Here are the ten that generalise.
A clock that never counts down
BellTab is a school bell countdown that lives in the browser tab. Building it came down to one rule the browser forces on you, a set of gates that caught more than I did, and a lesson about restoring old code that I had to learn twice in one day.
I gave an AI tutor a Sudoku solver, then used the solver to grade it
A weekend build — an MCP server over Puzzle Lab's human solver, an agent that gives one hint, and an eval harness that scored 52 hints against ground truth. The number came back perfect, which turned out to be the interesting part.