I like to ask "What's the worst thing about working here at Potential Co?" In addition to (potentially) learning what the group's pain points are, it also allow

I like to ask "What's the worst thing about working here at Potential Co?" In addition to (potentially) learning what the group's pain points are, it also allows the interviewer to blow off steam a bit (being on the other side of the table can be stressful too!) And if they dissemble or try to say that there are no downsides, well that's useful knowledge too.