A friend of mine forwarded my resume to the group leader. After a couple of days, I received an email asking for phone interview availability. The phone interview was only about 40 mins, basically he provided the information of the position and asked me my PhD work. At the end, he asked me for three references, but did not specify whether I'll be invited for an onsite interview. After about a month, I received a formal invitation. The onsite interview started at 10AM. It contains 7 one-on-one interviews and a 45mins presentation, and they took you out for a 30min lunch at noon. The 1:1 interviews mixed with technical and behavior questions. Everyone was nice but all the questions they asked were pertinent both to the position and your field. So I was pretty exhausted at the end of the day. You also can tell these engineers are really professional. Unfortunately, I did not receive the offer. However, the overall experience was very pleasant and precious. My advice is to refresh your statistics and undergraduate subjects 'cause most of the questions are not difficult but you may just forget the proper terms to answer them precisely.