2 Interviews overall. 1 with senior recruiter and other one onsite with CTO. HR interview was easy. CTO interview was also easy but I have no clue why I got rejected. He asked me 2 questions. First question was that an array is given and we have to find the pairs that has sum = 4. My solution: I provided my brute force solution O(n2). He asked for optimization, so I provided my answer in O(n) solution using hash tables. He asked me how hashtable lookup works and since I didn't know in-depth, I told him I don't know. He asked me why didn't you use binary search to solve the question through, so I replied binary search solution will take O(nlgn) but my solution is more efficient. In the end, he asked me why people still uses binary search than hash tables or hash maps. So, I answered him.

Initial phone screening was fairly simple and we just walked through my resume. HR asked me about all my projects and the programming languages that I am comfortable with. A major problem was the rescheduling of the technical interview done approximately five times which kind of sapped all my energy for the interview.