There were total 4 rounds excluding the HR round 1st round was purely based on DS/Algo 2nd and 3rd round was a mixture of Java, Multithreading, and System design 4th round was techno-managerial In the 4th round, the guy kept on prodding me about the elastic search which I had told him in the very beginning I have never used in my life but still, he kept on changing the requirement to see how will I change the parameters on the elastic search to return the response of multiple companies based on unknown parameters. Overall this round was around 60+ minutes and we just kept on moving around search which I had no idea about. All of the rounds prior were good but this one just took the cake. Just an advice to the company HR if you guys want someone with a specific skill set you should only take candidates who have prior experience on that instead of wasting their precious time.