After OA, I had a LLD round where I had to use best OOPs design principles and design patterns to basically provide a running code with test cases. The question was in multiple parts and the difficulty increases at each level.

got OA in November via hackerrank, really hard DP problems. cannot solve any problems and was rejected several days later. The problems were even very hard to understand, didn't have a great experience, seem they only want geniuses who won competitions.