I told them about a piece of equipment that, on the surface, had a very simple task. The operating environment, however, was very challenging. This answer drove LOTS of discussion into the how's and why's that moved my technical decisions. As a hiring manager, not only am I stealing their question, but I'm stealing the whole LINE of questioning they shot at me afterwards. Both teams asked me this same question, but drove it in different directions i.e. they're skilled interviewers.