Microsoft Software Engineer - Internship interview questions

Applied through a career event in our university. A week after got an email for on-campus interview. Interviewer seem to be not happy to being there. There was an easy linked list question which I solved and a few straightforward behavioral questions. No resume related talk. Interview wasn't selective at all. I'm not sure how they filter down depending on these questions. I would expect more sensible and challenging interview from Microsoft. After 4-5 days from the interview, they emailed generic rejection.

Four rounds of tech interviews. One question each. The difficulties overall were like easy~medium problems on Leetcode. People were all very nice. The interviews were all in the HR building, which was apparently not very spatial.