Apple Hardware Engineer interview questions

First is the phone interview with HR, then the technical call in the form of video call Interview. Finally, the interview is with about nine group members in the form of video call interview (final round of on site interview). The on-site interview is a little bit dense.

Very experienced interviewers. They asked and talked about detail questions, mostly about optical design, control of hardware, LiDAR systems, time of flight measurement. Each of the interviewer has one specific area of focus, probably based on the project they are doing right now. Looks like apple is making efforts to the autonomous cars and face ID et. al