01 · Writing
Notes from building things.
Short engineering write-ups. The kind of specific, load-bearing bug that only shows up when you ship and operate your own software. Mostly postmortems, and things I wish I'd known first.
6 min
Three kernel panics getting a 284B model onto a 128GB MacDeepSeek-V4-Flash is a 284B-parameter MoE model. My Mac has 128GB of unified memory. Getting them to run together took three real kernel panics before I found the config that holds. The answer was pure CPU, not the GPU.
5 min
A ratio metric and an absolute-diff tolerance froze my dashboard for three daysEvery health check stayed green while a metric sat frozen for 72 hours. The culprit was a threshold constant named NUMERIC_TOLERANCE_PERCENT that compared absolute values.
4 min
Apple renamed one word in a report, and my analytics silently fabricated installsA substring match on a report named "App Store Downloads" stopped matching when Apple renamed it to "App Downloads." The fallback returned zero rows, which got read as a clean zero.