Amazon Software Engineer interview questions

Had an online technical assessment that was, as usual, DSA and Algorithms-based. 2 problems in total; 1 easy and 1 medium-to-hard. The easy one was do-able within 15 minutes while the other one took some brain power to solve.

Had the amazon onsite loop of 4 1 hr interviews. 2 of the interviewers were really good, asked me relevant questions and also gave hints while answering those questions. 1 interviewer literally asked me a question which was very difficult(something related to disjoint set), I was not able to solve it even after getting a lot of hints. The last interviewer was very rude and asked system design questions even in my behavioral round like he dived deep to the system level. Also for coding portion he asked me a low-level design question, but the recruiter told me it was going to be a DSA round as well. I did not brush up on OOPS concepts because of that. Totally not a good experience starting from recruiter to the individual interviewer level.