I write backend services in Go and Python, and spend more time with Postgres and Linux than I planned. This is where I keep the notes that do not fit in a commit message.
Three papers I keep re-reading about inference cost
Paged attention, speculative decoding, and 4-bit weights — what each one actually buys.
Reading TCP socket states without netstat
netstat is missing from most minimal images. Everything it knew is still in /proc.
What actually fits on an 8 GB card
The weights fit. The context is what gets you.
The eval set was in the training data
0.92 on the holdout, 0.71 in production. The holdout was the problem.
A cron job that ran twice
Nothing in the logs said overlap. The second copy just started, and both wrote the same file.
When a Postgres index made the query slower
A composite index looked like the obvious fix. It made p99 four times worse for a week before I noticed.