First round was a coding round. I asked the interviewer some clarifying questions and I realized that a clean, extensible solution is what they valued the most. It's OK to store data in memory and not use a DB or a framework as long as the code quality is good. I also outlined my high level design and approach to the interviewer before writing code. I was given 1.5 hours to finish the solution and I managed to finish it in that time. The interviewer went through my code, asked some questions about what would change in the solution if we introduced a DB, etc for which there would have been minimal to no change needed. Despite asking clarifying questions to try and understand what the interviewer is looking for, explaining my thought process and having a working solution at the end, I was rejected. The interviewer was very generally very passive and seemed like he wasn't paying attention. Moreover, he had been working at Udaan for just 4 months.