I gave myself carpal tunnel replacing over a hundred copies of the same five lines of code with an n² complexity with a single implementation, so then I could fix the perf issue later. -500 lines over a holiday week, which was nice, but not as nice as landing the changes to the shared function and making 2/3 of the app 10x faster with the test data, which was ultimately going to be a fraction of the real data.
Don’t large scale refactor in vim folks, especially if you haven’t memorized all of the shortcuts (I hadn’t discovered block indent until weeks later. Ouchie)