Ok maybe it is different as I did not apply for permanent position for about 25 years but I have developed/helped to develop many products on consulting basis for other companies and had to go to numerous interviews. Here is my experience:
Some companies are hiring a pie in a sky while other have real problems and want to hire people that can solve real problems. Hence 2 type of questions:
1) Write me working Lisp code of some exotic sort algorithm, oh and btw what that Hermite–Minkowski theorem is about.
2) They ask what you've done, how you did it, some references and how you can help them to solve their problem.
When I smell #1 I just apologize and leave. #2 can go either way but at least you're talking to a reasonable people with real needs.
Some companies are hiring a pie in a sky while other have real problems and want to hire people that can solve real problems. Hence 2 type of questions:
1) Write me working Lisp code of some exotic sort algorithm, oh and btw what that Hermite–Minkowski theorem is about.
2) They ask what you've done, how you did it, some references and how you can help them to solve their problem.
When I smell #1 I just apologize and leave. #2 can go either way but at least you're talking to a reasonable people with real needs.