Apple Product Design Engineer interview questions

Meet on campus at a university event, left my resume with recruiters. Then they called for a follow up phone screen (30 minutes), but the interviewer was running late. They asked all technical questions, very much on the mechanical engineering and not product design side. Basic engineering fundamentals, beam bending, kinematics, manufacturing, and material properties. Was friendly and explained the job description well to me.

Was first contacted through email to schedule the first round of phone interview. The process was pretty smooth and the interviewer was well prepared. Then I was scheduled another round of phone interview where the interviewer didn't seemed that well prepared.