- 31 August 2026 · 7 min
What a prompt change actually costs
Everyone asks whether the cheaper prompt hurt quality, and almost nobody answers with evidence. Most of the difficulty turns out to be statistical, not architectural.
- 30 August 2026 · 5 min
Bounding a billed API with the shape of its cache key
A public endpoint that calls a metered API is an unbounded bill. Sorting two values before they become a primary key turns cost from a function of traffic into a function of distinct questions.
- 28 August 2026 · 7 min
Free tiers are a design constraint, not a discount
What changes when zero infrastructure spend is a hard requirement — including running a consumer product's LLM layer entirely on free open-weight models, and the measurements that made it work.