Sorry to hear about your frustration. A lot of people can sympathize, but I can assure you that nightmare codebases can happen in statically typed, object-oriented languages just as easily as they can in dynamically typed, functional languages. Not sure if there's one best way to prevent it. Applying the 'unix philosophy' for better modularity can help; structuring a JS codebase from composable modules is an example. Nowadays I try to approach code with the mindset of "what if we wanted to turn this into a standalone, open-source npm package." Even simple things like writing consistently good README's in every repository can help. If you haven't yet, unit tests and linting should be part of your build pipeline, too.