[user5994461]

I have never seen a company that didn't store some credentials in their VCS.

[oneweekwonder]

To the point where you see weekly TIFU /r/cscareerquestions post on a junior using training material and then accidentally trashing the production db.

[staofbur]

That doesn't happen because you don't let them have the credential vault keys. In fact no humans get them; just the build and deployment pipeline.