they give me 2 array based problem in problem those I need to solve using optimal solution explain the time complexity as well.In L1 round they are basically focusing on DSA.

First round DSA where 2 questions were there, cleared it. Then second round was Database design, caching where there was 1 question to design the database tables with columns, relationship. Also need to specify APIs you would define for the same. Cleared the round. Third round was managerial which was mix of behavioural and system design. I missed 1-2 cases/scenarios however the design was fine. Then I got to know that I didn't clear the final round. I was surprised so I asked for feedback. After following up with HR for 2 days I got feedback on what's app. I came to know that my expectation is more than their budget while talking to HR. HR already took my expectation details before final round, I don't understand why this was not communicated earlier that they have budget constraint. I didn't find this professional. Also rejecting the candidate initially with false reason is not something company should do. Tell the actual reason. Also hr should take expectations details at start itself rather than at final round. It is a waste of time, energy and effort.