Applied on careers page for Software Engineer Internship and got contacted by a recruiter 3 months later. Got scheduled a video screening interview involving two technical questions: 1. Check for palindrome in string ignoring special characters. Ex: &^ab*ab is a palindrome in O(N) time and O(1) space. 2. Validate Binary Tree for being a Binary Search Tree in O(N) time and O(1) space. Then I was scheduled a video onsite interview: 1. Determine whether array contains a contiguous sub-array whose elements sum up to a given number in O(N) time and O(1) space. The interviewer didn't seem very interested at all in interviewing me and seemed in a hurry. I solved the final interview question as well in the most optimal time. But I did not know this solution from the beginning. So I had to develop this algorithm myself in the interview. This took some time and getting there involved changing the initial algorithm I had thought of. Got rejection call 2 business days later. Reasons were: - I didn't clarify the new approach when my original approach did not work, and started coding straight-away. But I clearly remember saying that original one doesn't work and needs changes rather than simply going on with my work. Also I had no clue about the new approach I was going to implement, and I was explaining the stuff along the way as I developed the solution, rather than explaining it all in the beginning. I don't know how else could have I clarified my approach because I simply could not have clarified in the beginning other than explaining that it needs changes and doesn't work this way which I did. - The approach seemed overly complicated to the interviewer. I was considering to add more things in the solution to make it more efficient, when he asked if it needs anything more (but I didn't when he pointed out its not required), which was termed needless and considered "complicated". - I didn't test any other test cases other than the ones given to me. But I didn't test other test cases even in the first interview. So I don't know why I was expected to do it here, since it was supposed to be same format as the last one as told to me by the recruiter. Overall, this didn't seem a fair rejection to me and I was not satisfied with the result.