The first interview was an on-campus interview. I was asked questions on basic electronics - ex. how to design low pass/high pass filters, describe a project etc. The 2nd round was energy sapping. Had a 6 hour interview (includes a 1 hour break for lunch) with 5 different members of the team who quizzed me on every thing I had learned in the past four years of engineering. I was tested on analog/digital electronics, programming (basic C/C++ questions) and digital signal processing.