Earlier quoted context omitted.
I think “what is an interface” would trip me up actually, haha. My thought process was: Well, most of the code I use uses a Reverse Communication Interface. But, I think these are pretty old-school projects, maybe I should start by talking about the Object Oriented interface to the library that we recently did. Or maybe I can talk about the file IO based interface that I did, it was extremely cursed but kind of funny…
"Can you clarify what you mean by interface?" is the right answer
As a matter of fact, yes, that's the best approach, but only because if you receive a question like the OP's, you've already lost and have to just take a blind bet.