The interview was smooth.There were 3 rounds of DS and algorithm. In my first round, the interviewer was good. She introduced herself and the company. Then she asked two DSA problems, in which i solved both but not efficiently. First question was on matrix and second one was on backtracking and recursion.I clear this round but she advised me to practice hard so i did. My second interviewer was not great and engaged. He just given me one question and went to work on his own. It was a simple question and involved some math. I didnt able to crack it fully. But i given him the brute force approach. My third interview was on the same day. He was a senior software engineer and looks very professional. He ask to me to create a stack with O(1) operation for insertion,deletion and max.Second was on Dynamic Programming in which i have to just give the approach. I solved both the questions with optimal approach After this round HR told me that my second round result is average and for third round it is thumbs up. So we will take your fourth round. In my 4th round, Interviewer was little bit not in mood. He is looking vague. He asked me about my projects and all then he given a No of Palindromes question which i solved it via giving him the exact approach and code. Next day HR call me that i have not cleared the my 4th round. I don't know what happened or where my interviewer got offended in my last round although i answered it correctly. He was not that professional.