A recruiter located me online and asked If I were interested in an R&D Software Engineer position. We spoke through email and then later setup a phone interview with someone I would be working with. The phone interview was easy, I was asked about my experience, and a few questions that I considered to be incredibly easy (but, I have been doing this for a long time).
After passing the phone interview, I was invited to an on-site interview. The on-site interview was with 4-5 different people and lasted about 4-5 hours. It was easily one of the longest interviews I've been though. They asked me a lot of hardware engineering questions, an area I have experience with, and asked even more software questions. Again, given my experience I felt it was all really easy; but, I think most people would find it super stressful. --In fact, I know someone who had a similar interview last year for a SW position, he thought it was the roughest interview he'd ever had... I spoke to him after mine, and it sounded like we got the same questions. If your at the top of your game, you'll find it easy... If your not in the top 10% in your field, You'll be destroyed.