Microsoft conducts hiring drives and keeps multiple rounds on same day. Two rounds were kept on same day. I asked to keep third round on another day because of non-availability. This was for the data security team. First round was DSA round. It was basically to find connected components. I coded the entire solution using Union Find algorithm with Path compression and Union by rank. When I discussed the solution and coded it in 15-20 minutes, he was okay with the solution. He went through my code and started speaking rudely that I am looping through my code extra times which is unnecessary. I tried to tell him that I exit early as soon as I find the answer. He did not listen to me and later apologized when he realized that I had already done what he was adamantly mentioning. After this point, he already decided to reject me because he realized that he was wrong and it reflected in his behavior. We had 30 minutes left. I asked if he wishes to ask me a second question. But instead he utilized this time to be condescending towards me. At first, he asked me the complexity of my code which was optimal. Then he immediately interrupted to tell me that this is a textbook solution and he needs an alternate approach to this(multiple source shortest path). I told him why Union Find is better and he agreed but he still went on for 15 minutes, roaming in his own room with his wife in the background roaming as well while I listened. After he was done, I tried to be respectful and asked him if he is happy with my solution or if it is optimal. He explicitly mentioned more than twice that he is satisfied with my solution as it is optimal. We still had 10-12 minutes left and he opened the floor for any questions so we simply had a chat. Second round was with two interviewers. We discussed a bit on my experience and he tried to belittle my work experience. He proceeded to ask me a very poorly formed question. "Write a Get Api to fetch product details if you are passed a page number in the parameter". I clarified it further and he kept giving unhelpful answers, which were vague, conflicting and unnecessary. I understood that he is possibly looking for an LRU cache implementation. But when I told him the classic Dictionary+List approach, he rejected it. He could not understand how cache works at the OS level and his requirements kept changing. He came unprepared and did not know how to conduct interviews because he kept improvising and taking the interview in various directions instead of being clear in his expectations. To mask his poor skills in front of the senior engineer, he made a remark on me stating that I need to brush up on algorithms. This is after I already gave him the implementation of LRU cache and he is the one who rejected it. I understood that he is going to give a negative feedback. It was not even a tough implementation but he made the interview difficult. Recruiters ghosted. At last when they answered, they stated that I got No Hire for both rounds. I was not given any other feedback. I wanted to know why I was given No Hire in the first round because it looks like interviewers rejected because they wanted to reject. I spent my time to be insulted by Microsoft employees. The preparation that went behind these interviews led up to this outcome. As I did not expect this, I could not have known until I experienced it. In hindsight, it is better to be rejected by unprofessional managers than to work with them and regret it later as one spends half their time at workplace. I hold proof that I gave the right answer and also proof that the interviewer intentionally gave No Hire. I will expose this interviewer one day and with that, I will expose Microsoft and this Data Security team for prejudice during interviews.