A large chunk of third party usage is open source Google libraries like Guava. Anecdotally, I don't end up using that many libraries from third party. As for

A large chunk of third party usage is open source Google libraries like Guava. Anecdotally, I don't end up using that many libraries from third party. As for JavaScript, the hassle of importing the entire transitive closure of an NPM library you want into third party means it's much more attractive to go with NIH syndrome. I looked at importing ESLint, but it has something like 110 dependencies.