LinkedIn Software Engineer interview questions

Recruiter phone call, one technical phone screen, and if you're good enough there, two more technical phone screens. This is for people located far from LinkedIn (so those in the Bay Area will experience an on-site interview).

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.