Applied online. Had two screening interviews.

The first interviewer was clearly a "newbie." He seemed more stressed than I was, which made the interview very uncomfortable. He had a strong accent, but that wasn't the worst part; he was always saying things and then quickly taking them back.

The second interview was smoother. The interviewer was clearly more experienced, though I found him a bit cold and it wasn't easy to get information from him.

Bottom line: Interviews are also about people. Try to adapt and don't be surprised. Surprisingly, a large majority of interviewers are there to help instead of trick you. Just don't give up on getting the most out of them.

NDA. Just be comfortable with data structures.