LinkedIn Software Engineer interview questions

I applied online and got contacted by recruiter the next day. He was very nice and quickly arranged a phone screening. The interviewer called me and asked me two questions - two sum problem, and parenthesis matching. I missed to handle one edge case and the next day got a rejection call. The problem which I see here is that in one of the questions, I was talking about Java String internals, how a String is backed by a character array, and she had no idea of what I was talking about. That might have offended her. I have solved two sum problem and parenthesis matching problem many times before and I do not expect to get a rejection, but I got it. I am a PhD and have 4 years of experience.

Interview process started with telephonic interviews with the HR in mountain view. I would receive calls at 11 PM in the night. Being a late sleeper I did not mind this. The HR consulted me for interview time, and made sure I was comfortable with the process. I technical rounds on Skype, which lasted around an hour. The questions were standard, and I was able to clear them easily. After this there was an HR round, which had quite run of the mill questions, like 'why LinkedIn?' and soon the HR was on to the topic of compensation and my role with the company, at which point I knew I was in.