Prompt engineering is just interface design
Treating prompts as APIs — versions, contracts, and tests included.
The numbers below are from my own machine and my own workload. Treat them as a method, not a benchmark: the point is how the measurement was taken, not the exact figures it produced.
Where I started
By the end of this post you should be able to reproduce the whole thing yourself in under an hour, including the parts I got wrong the first time — those are marked so you can skip them if you're in a hurry.
What surprised me most was how small the final change was. Most of the work was understanding the problem precisely enough that the fix became obvious, and that understanding took far longer than the fix itself.
- Capture the current behavior before touching the code
- A second point, kept short on purpose
What went wrong
What surprised me most was how small the final change was. Most of the work was understanding the problem precisely enough that the fix became obvious, and that understanding took far longer than the fix itself.
I kept a log of every decision during this project, and reading it back a month later was humbling: the choices that aged well were the boring ones, and the clever ones all came with a footnote I hadn't written yet.
Everything above is the short version. The full write-up of how this played out is a story for another day — for now, the takeaway is simple: treating prompts as apis is a decision you make once and revisit deliberately.