LinkedIn Senior Software Developer interview questions

First, a 1-hour phone screen that focused on my resume and system questions, followed by a short coding question using a collabedit. The interviewer pointed out a small mistake I made in the coding question, and let me fix it (was a stupid one). He was very nice and easy to understand. Then we proceed to an on-site interview. 6 rounds, 1 hour each. One round on communication, two rounds on system design, one round with hiring manager, one round on coding, and one hour of lunch. I had 2 interviewers scheduled for 4 out of the 6 rounds, but one of the interviewers did not bother to show up. Based on the feedback from the recruiter, I feel like the system design questions are more about a mind-reading exercise than assessing my analytical skills. One of my system design interview was with two - I think - not very experienced interviewers, and perhaps I gave them an answer that's not what they expected. I addressed every potential weakness of my design they brought up (which they didn't let me finish saying what's in my mind in the first place), and from the recruiter's feedback now I understand they weren't happy about my answers, because it's not exactly the one they had in mind. They said I had "challenges" in those interviews, which I respectfully disagree. I understand some questions are designed to be vague and expect me as a candidate to ask clarification questions, but the interviewers decided to stay abstract. So I can only answer in very general terms. LinkedIn needs more experienced interviewers to assess a candidate's skill. Since most of my interviews had two interviewers anyway, you might as well assign one experienced and one not-so-experienced interviewers at the same interview.