My interviewing style has changed over the years, and of course it depends on the type of Engineer you're looking for, but in general, what do you ask an Engineer during an interview? What should you get out of it by the end?
I did about 200 interviews at Google for the FE Engineer role and was on a hiring committee for a while. Recently I've been on the other side of the interview process.
In general I like open ended coding-design questions, where I examine the process in which people work through a problem. I especially hate "trick" or "a-ha" questions for anything other than warm-up; simple if you've seen it before, but often inconclusive otherwise (e.g. implement divide without / or % operators).