Had a first round with the hiring manager that discussed projects I've worked on. Second round was a panel of people asking me technical questions. They insisted I derive any answers from first principles, and they clearly had an answer they were looking for. When I failed to provide that answer, they just let me flail, providing no additional guidance. I asked them what is one change they'd make to the company - they said they started cutting fat but they need to continue cutting the dead weight. Yikes. At some point during the interview the interviewers started arguing about the best method to solve a problem. Double yikes.