HR reached me through email and scheduled phone interview with one member in machine learning group. First round of phone interview is about some linear regression knowledge and an algorithm problem. I did pretty well and they move forward to next phone interview quickly. I did well in second time too. But fail in the onsite round. Onsite has five meetings in the Chicago HQ. Some interviewer is friendly but the team leader is so serious that I felt too nervous to be smart in answering the questions.