Short writeups on bugs I've fixed in open-source projects, patterns I've learned building AI-powered systems at work, and the kind of subtle software behaviour that's only visible from the trenches.
chokidar filterA 2-line fix in NestJS CLI's SWC watcher. Two layered bugs in one predicate: a string-format mismatch on file extensions, plus an inverted boolean that turned the ignored filter into an included filter. A README save was triggering full TypeScript recompilation.
list.reverse() returns NoneA 1-line fix in BullMQ's Python port that turned on the universal lesson about Python's mutating-vs-returning method conventions. .reverse(), .sort(), .append() — they all mutate in place and return None.
A 2-line CSS fix in VS Code that taught me how user-select: text cascades through every descendant — even the decorative ones. The fix for my own misread of the bug: stop looking at JavaScript, start looking at the cascade.