EFI Principal Engineer interview questions

Interview process started with a Call form recruiter and then scheduling an in person Interview (which was not necessary) - this could have been virtual also. Interviewer might be very knowledgeable, but he was not very much prepared for the interview. He thought I had completed one round of interview over phone/virtual. He was shocked that it was my first interview with EFI. Started with basic questions about C++ and then he wanted to know how things works at the background. I tried to explain him. The way he was asking the questions were also not that great. He was asking like is it like this or that etc. Overall I had a not so pleasant interview experience. I just wanted to quit the interview at the middle and come. It went over 1 hour 15 mins and then I was told to go. Thanks.