I think a "good pipeline to prod" with sufficient automated tests to ensure nothing is broken is the exception not the rule. Even in places that think/say they have a "good pipeline to prod". It's something that takes a shocking amount of engineering effort to do well, and tons of discipline to maintain.

Hire a test engineer to manage all of that - it’s a full time job but an important one!

Totally agree. I've joined companies where there was literally zero test coverage. All tests were done manually. But then if you have bad test coverage, then you shouldn't be using something like this.

should be okay is definitely not enough for me to ship things to production.

And while I do have automated tests, they might sometimes stub system calls as I'm mostly testing my code to keep things stable and fast.

I'd rather explicitly declare my dependencies and use the same container for development, test and production to feel much more confident that it includes actually everything that's needed.

with good pipeline and knowledge about your app you should be able to ensure it works without much of a problem