Writing
The long version of things that didn't fit in a case study.
The edge said HIT. The browser asked anyway.
Cloudflare was caching this site's assets and reporting it on every response. The browser was still revalidating all six of them on every visit, because of a default header I had never read.
What changed when an agent started using my CLI
rmine was built for two callers from the start: me at a terminal, and a coding agent. The design decisions that only make sense because of the second one.
Three agents that don't trust each other
An effort estimator built out of three subagents. The decisions that mattered were about what to withhold from each one, not what to tell them.
The sync job that took half a day
A device sync was running 12 to 15 hours against millions of software records. The fix was batching and eager loading, but the lasting part was measuring first.
I used it internally for two years before publishing it
bitwise_attributes packs boolean flags into one integer column. Most of what makes it a library rather than a snippet came from the gap between those two things.
Building on a DOM that isn't mine
A 300-line Chrome extension that adds a translate button to WhatsApp Web Status. One commit fixed four bugs, and all four came from the same wrong assumption.