In retrospect of course it's always easy to criticise, but still, the diff is really cringeworthy. The deleted code is very specific-looking. Nobody writes tha

In retrospect of course it's always easy to criticise, but still, the diff is really cringeworthy. The deleted code is very specific-looking. Nobody writes that just casually or out of ignorance. Also it is what was at use in production. It's very naive to just go and replace that with nice-looking, shorter code. Key lessons: - Understand what you are deleting - Treat production code as sacred - Add reasonably extensive comments for delicate code (as the original one). Git commit messages aren't enough. - Try out infrastructure changes in production-like staging servers. I really doubt they properly did, as they say the "majority" of 17M requests failed.