LinkedIn Sr. Software Engineer interview questions

1 phone interview and 4 or 5 (don't remember) onsite interviews. The process was decent overall until the very last interview, the hiring manager seemed a bit condescending and asked me multiple times what the purpose of my Master's degree was (for context I have stellar degrees from a top five US university in CS for both undergrad and grad school). He still passed me in that interview, but seemed very skeptical of my qualifications, I can't imagine why honestly (sexist?). After the onsite, I got a call from the recruiter who said I had good feedback on all but one coding interview which they wanted to redo. When I got to the interview, they had actually set up a system design interview for which I was somewhat unprepared for but still gave it my best shot. I then emailed him and asked him what happened with the scheduling and why it was last minute changed to design, but he didn't bother to respond and simply rejected me. I don't mind being rejected generally but I felt that it was completely unfair that he essentially ghosted me after putting me through 7 different interviews and completely wasting my time. I would never recommend anyone apply or work here just by the sheer disrespect I experienced.