Stuff I Wrote
Notes on backends, prompt tooling, and the small decisions that quietly decide everything later. Mostly things I went looking for, didn't find, and had to work out the slow way.
The Demo That Parks One Time In Five
I built a car that parks itself by scoring a menu of seven sentences. Then I took away its map, gave it ultrasonic sensors, and watched it get four times worse.
The Normalisation That Picked The Worst Answer
Scoring a fixed menu of options instead of generating text: the maths, the one-pass trick, what it guarantees, and the default that hands 99% to the worst reply.
The Value Of A Closed Feature Request
My library has a page listing what it will never do. It's the most useful page in the docs, and it's the reason people can adopt it.
Prompt Tests That Cost Nothing
PromptKit 1.0 is out: prompts as files, a linter that finds the typo before your invoice does, and eval suites that run in CI with no API key and no bill.
Rendering A Prompt You Did Not Write
The moment prompts become files, they arrive from places you don't control. A template engine with defaults on is a code-execution primitive.
The Prefix Match That Tripled The Bill
A cost estimator that is confidently wrong is worse than one that says it doesn't know. How a two-line convenience priced Opus 4.5 as Opus 4.
A Version Number Is Not An Identity
Every prompt file has a version field. Nobody bumps it. Hash the content instead, and your cache stops lying to you.
Prompts Belong In Version Control
A prompt is not a string. It's a dependency with a price tag, and it belongs somewhere you can review it, diff it and roll it back.