I've never heard of giving applicants material before the interview. More commonly, I think companies give new hires (especially interns) a book or some material to read before their start date, but usually the investment comes after the decision.
Did the book shape the interview? Like if I didn't read it, I'd have a hard time? Or maybe even if I nailed the book, but didn't know anything else, that'd be bad?
The books did not shape the interviews, and we were careful to tell candidates that they shouldn't treat them as homework, and they could probably do just fine without reading them at all.
Did the book shape the interview? Like if I didn't read it, I'd have a hard time? Or maybe even if I nailed the book, but didn't know anything else, that'd be bad?