xto10x Interview Experience

I was initially contacted by a recruiter for the interview process at xto10x, which consisted of four rounds.

The first round, lasting 30 minutes, was an exploratory discussion with the hiring manager. We covered standard behavioral questions and discussed my previous projects. I received a positive call afterward to schedule further rounds.

The second round, a 2-hour session, was focused on Machine Coding/Design. My task was to design and implement a working code for a bowling alley. I felt I presented a good design and a functional implementation, and the interviewer seemed impressed.

The third round, a 1-hour Data Structures and Algorithms session, presented two questions. The first challenge was to find the oldest number with a frequency of one in a stream of numbers. I proposed a solution using a queue for order and an unordered_map for counts, aiming for O(1) retrieval. However, I noted that in certain scenarios, like 1,2,3,4,5,3,4,1,2, removing elements could degrade complexity to O(N). After some discussion, I suggested a Double-ended queue, but this did not fully satisfy the interviewer. We then moved to the second question, which was a standard BFS problem, and I provided a solution for it in just a few minutes.

The next day, I received a call informing me that I had cleared the technical rounds and that an HR & Hiring Manager combined round would be scheduled for the following week. However, the calendar event was cancelled the day after. Upon enquiring with HR, I was told that they had re-evaluated my performance and I was rejected due to my performance in the DS/Algo round. It was quite a sudden turn of events. Overall, despite the unexpected outcome, the interview experience was generally good.