I applied this position via their website and got the phone interview invitation very soon(less than 3 days). The interviewer wanted to get how much I knew about the firm. The coding question was running through a shared coding platform without test cases. So I wrote solution class and test cases. The question was initially mediate followed up a hard one. I got the onsite invitation 2 hours after the end of the phone interview. In Berkeley, I got a 4-round back to back interview from 9:45 am to 4:30 pm. The first round was somewhat easy. I was required to implement a special data structure to complete that coding problem. The second round was lunch interview during which I was asked about C programming questions. The third round was a little hard for me. The problem was very long and it had four stages to accomplish. I just finished the 3rd one. The last round was about the graph. Interviewer just wanted me to give an idea and discussed the feasibility of the idea together. The whole process was smooth except that I didn't communicate too much with the interviewers in the 2nd round. Got refused two days after back from Berkeley.