Until recently I prided myself on having a reputation as a tough job interviewer. I've espoused the importance of design problems and case interviews (a style thoroughly ingrained in me while at BCG) as these questions cannot be completely prepared for and so I believed they truly tested the candidate. However, when I got tripped up on a very casual case-like question at a dinner party last week, I began to wonder if this was a good method and what in fact was the best interview technique.