Code hotspots

Complexity costs money only in code that changes. A gnarly file untouched for four years costs nothing. A moderately complex file edited twice a week absorbs the bugs and the time.

So the ranking signal is not complexity:

hotspot = change frequency x complexity

Git already recorded which code is hard, for free. Every commit to a file is evidence that somebody had to understand it. This is behavioral code analysis, from Adam Tornhill's Your Code as a Crime Scene.

Step 1: change frequency

git log --format=format: --name-only --since=12.months \
  -- ':!*lock*' ':!*generated*' ':!vendor/*' ':!*.snap' \
  | sed '/^$/d' | sort | uniq -c | sort -rn | head -25

Use a 6 to 12 month window, matching how far back the team remembers. Longer windows include code that has since stabilized. Exclude lockfiles, generated code, vendored directories, and snapshots.