Apple Mechanical Engineer interview questions

I was contacted through LinkedIn by a recruiter. I did two phone interviews (one pretty general, another one more technical) then I went to CA for a full day of interview. I met 6 different persons, did 1 on 1 interviews with each of them and them worked on solving a problem (on a white board) with 4 of them. The interview was very technical, in terms of fundamentals as well as applied techniques and hands on knowledge. I did not get a job offer after the interview, I suspect because of my lack of mass production design.