First talked to an HR person, mostly about my previous technical experience/projects from school, work, or internships. I was invited to an on-site interview where two hiring managers conducted the interview. The interview was mostly (95%) technical. It consisted of about 45 minutes of problem solving (like in a test). The problems were mostly circuits and electronics based (know your op-amps and filters). They wanted to make sure I know my basics and the way I think and solve problems. After the "test" there was some time for me to ask questions.