I had a phone interview that lasted about 20 minutes. They wanted to know my background and asked me a few simple questions about how a display works.

I didn't think the call went all that well, but I was called a few weeks later to come out for an onsite interview.

The onsite interview was interesting, to say the least. It was a full 8:30 AM to 5:15 PM interview. I started off with the HR manager, then it quickly shifted to a revolving door of engineers going one-on-one with me and the whiteboard.

I was repeatedly asked to explain how a display worked, explain my prior work, and explain various polarization phenomena.

The hardest part of this interview was its unrelenting technical nature. No one cared about any other skills I could bring to the table, only about being a technical robot. There were no 'brain teasers' in my interview.

Example question: Explain to me how polarization physically works (not E&M theory).

The problem with this kind of question is that several explanations could be given. However, the interviewer likely has a specific answer in mind, making the question particularly leading.