I've once been rejected in an interview because I found a solution that the interviewer didn't think would work, spent half an hour trying to prove me wrong rather than trying to expend the smallest effort to understand - even after I proved it was correct. I was quite glad they showed me a bit of the culture though
While this dev you encountered might have had no idea what they were doing, a most charitable explanation is that they may subscribe to the idea that the "unit" is a business usecase within a single service (often a 1:1 correspondence with an endpoint, but sometimes even more than one, e.g. a form upload with a separate signed upload step to a 3rd party service).
FWIW the concept of small/medium/large as presented in the Google testing blog is a much more useful denomination.
What is a component? A global variable, a pure function, a procedure, an endpoint, a business usecase, a microservice, a microservice fleet?
What is the whole, if not the same list of questions just asked in backwards order?
It gets worse: Once you arbitrarily come up with one definition that you stick with in your project, does the definition you chose leave little to no room for interpretation? Do all kinds of tests that are worth writing fit neatly within those definitions?
Technical terms that are so loosely defined we can do without, for only two things ultimately result from their use: Apathy, or madness.
That’s what I see interviews as: I’ll show you my culture if you show me yours.
There’s a lot of fuzzy factors like willingness to admit lack of knowledge, eagerness to learn, ability to cooperate.
"I just want to be left alone to program" seems like a perfect fit: will do the job, will not ask for anything.
but let's not derail, "no i dont want to go to company parties" = "doesnt want to socialize" - "doesnt want to submit to the company" - "will probably be a hassle to work with" - "can't communicate" - and so on.
again, think hard about a different career angle in tech if you dislike these things, you might enjoy it more