That is a very reasonable complaint, and I think the core devs (of the language and of the flagship ecosystem projects) take it fairly seriously. For me persona

That is a very reasonable complaint, and I think the core devs (of the language and of the flagship ecosystem projects) take it fairly seriously. For me personally, it has been incredibly empowering to be able to mix and match very diverse packages, but maybe I am just used to defensive coding: I start with tests, including randomized tests and contract tests. On the other hand, though, I have not encountered more bugs in the Julia ecosystem than in the Sympy or Theano (deprecated now) or Tensorflow or Pytorch systems when I was using them to build "sophisticated large computational packages". Maybe the happy users are just not as vocal, but that is a silly excuse.