I'm part of an interview panel this week. I have only ever given a structured interview before (all panelists have a list of the same questions, and we use the same questions for all candidates; cannot lead the candidate; etc), whereas now I am being asked to evaluate the candidate for cultural fit, interest in the position (this is "just a conversation", we reached out to the candidate and do not have an actual open position), etc. I have the freedom to run my 1:1 interview however I see fit. We would consider the candidate for a hardware design engineering position at a startup firm.
In searching around on Workplace.SE, there's lots of input about what to expect as an interviewee, but not an interviewer. I want to ask good questions that properly evaluate the candidate without leading or otherwise biasing the process, and actually add value to our hiring process. (I also don't want to provide a bad candidate experience that might lead to a post on Workplace.SE!)
What types of questions should I ask the candidate?