I was contact by phone first, then the interview was scheduled via email. On the interview day, I met with HR manager:I talked how much I knew about the company, my interest, what I did before.
Met with engineering expert: I was asked several engineering questions, I could answer some, the others with some help from the expert.
Met with hiring manager: I was asked about some management interview questions, such as "Tell me about yourself", and others related to job requirements.