LinkedIn HR called, phone interview, then onsite interviews, HR was calling frequently to update status (good), one of the interview was just too cold, he wasn't very responsive throughout

The interviewer asked 2questions. One coding question although I wrote the package and relevant classes to be used to solve the problem. Interviewer was not happy, as I wrote code in Java and the interviewer expected it in some other language of his preference. They made me prepare DS, Algorithms, OS, System Design. And asked a non-relevant question not part of any of the subjects asked to prepare. They boast aroud their "Reduced Four" interview process. But, their interviewers need more trainings. Ethical interviews, unethical practices like the EU antiTrust fine.