Pre order traversal of tree, need to construct tree from list, no template given, got asked about my resume a lot, dive deep, asked about internship experience and research experience, relevant questions towards research

about my resume, bq questions, some fundamental questions, then a lc, finally the qa part, but it does not go smoothly. I feel the interviewer did not want to talk to me much

OA, followed by 3 rounds of onsite interview, all three rounds are coding round, 2 medium and 1 hard leetcode level coding, and one of the round asked some full stack related questions