I had got the interview scheduled from a consultancy. They didn't provide proper contacts and JD, had to wait for more than 1hour. The first round was cool and went fine. Second round they had asked me on Mongo which was out of JD. They had asked me to prepare for on-site round with senior management. I didn't hear from the HR for a week, after which I got to know I was rejected with no feedback or reason. They need to learn to respect others when they come to interview.