Vecna Robotics interview questions

Initial phone screen, video call with engineering manager then on-site interview. First two were completely fine and pleasant. The on-site interview was pleasant with most of the engineers. Friendly people. The higher engineer was particularly disinterested the entire time and not friendly. Completely understand the need for tough technical questions but facing away from the interviewee 3 hours into a scheduled 2 hour interview was frustrating. I was happier to get out than to hear back even though the interview felt like it was going fine. Was uninterested by the time I left which probably showed.