> A lot of rewrites could be avoided if people spent some time to actually understand what was done before. It’s a pretty safe assumption that the people who worked on the codebase before were as smart as you.

it’s not always a safe assumption.

planned a full rewrite of a product at last company. i knew things were fucked 3 months in. i started really planning the rewrite 1.5 years in.

that year taught me just how fucked it was: bugs galore, race conditions, crashing frontend, testing in customer environments, data loss, rolled their own security (users from any group could login to any other instance).

previous big brained devs really fucked it and there wasn’t much of anything to show for it.

i fixed a bunch of it. but it still needed a rewrite because they had built the wrong thing. which was the bigger issue i realised 3 months in.