We are interviewing for a principal at my work, and the directions from management are to find someone really good. Instead of tearing into their experience, m

We are interviewing for a principal at my work, and the directions from management are to find someone really good. Instead of tearing into their experience, my coworker is asking what you would use the X class for. Drives me fucking nuts. Who memorized all the parts of a random, mostly unused .NET class. I asked the coworker afterwards if he ever used said class, dude said no. How is that a fair question if it isn’t even used here?