We are replacing truly the most disgusting codebase I've ever seen right now, a WP instance (alright) highly customized (worrisome) written by pre-for-loop contractors (uh-oh) which has over 10k lines of jQuery (uh-oh) for a relatively small site, but all of the jQuery lives in one main.js (UH-OH) and executes on every page whether or not it does anything to that page. It's also written in such a way that it crawls the DOM so many times on huge HTML payloads that the entire page slows to a crawl as your computer fan winds up. You'll often get 10 seconds of non-responsive page after the first paint. There's barely any interactivity here as well, just a couple of modals and buttons.
As the client scaled up, they started having serious performance problems that rendered the site completely unusable for some users, and some pages were so bad on the backend that simply visiting a page could cause an outage. Refactorings were considered (minor ones attempted), but the code is so poorly written and brittle that it's actually easier to just fucking rewrite it, so they/we just do targeted performance enhancements, bugfixes, and minor updates while rewriting.
All that to say, the worst codebases I've ever seen are PHP monoliths, (though I've seen some rough Django/flask as well) shitted out by contracting firms which bill high rates for code written by juniors. People (particularly those who frequent this site) are way too focused on the choice of framework when trying to assess these outcomes.
As the client scaled up, they started having serious performance problems that rendered the site completely unusable for some users, and some pages were so bad on the backend that simply visiting a page could cause an outage. Refactorings were considered (minor ones attempted), but the code is so poorly written and brittle that it's actually easier to just fucking rewrite it, so they/we just do targeted performance enhancements, bugfixes, and minor updates while rewriting.
All that to say, the worst codebases I've ever seen are PHP monoliths, (though I've seen some rough Django/flask as well) shitted out by contracting firms which bill high rates for code written by juniors. People (particularly those who frequent this site) are way too focused on the choice of framework when trying to assess these outcomes.