after two midnight phone interviews i was flown in several days in advance to allow me to kick the jet lag.
i then spent 8 hours being asked hard, technical questions by 9 different people, i think.
a couple of the questions required epiphanies which i happened to have - so i was happy - but in general, i don't think those make very good interview questions. many fine interviewees are nervous and in no state to have epiphanies. conversely, you could have a middling interviewee who has heard the question before.
the final interviewer presented me with an offer. very impressive turnaround.