Was refereed by friend, received a call from HR asking about background and fit. 1st phone interview was with a data scientist which asked various questions in sampling, unix commands, machine learning etc, also some puzzle , overall lasted an hour. After a week later got a 2nd phone interview from senior level data scientist whose voice was pretty thick and difficult to comprehend, but was asked machine learning questions, concepts of boosting and boostrap aggregation and communication entropy theory. After this got in onsite round full day 8-5, started with 1 hour presentation of your current work. Interviews were focused on technical questions and almost everybody was asking lot of questions. I was lil tired of speaking the whole day from 8, at 3 pm, had interview with data scientists who were trying to play good/bad cop, one of which started talking in loud voice and giving difficult questions. It ended at 5pm. It was very exhausting experience. Every interview was good apart from that good/bad cop one. After the interview, contacted with HR and hiring manager who said they are waiting for other people for interviews and should take 2 weeks. Contacted them after 2 weeks, they said again 2 weeks , and so forth, they were just not ready to give a decision until i got offer from another company and i asked a response in which they said, they already decided on a candidate.I felt bad not about not getting selected but the time i invested in the company giving 3 telephonic interview, preparing seminar and taking day off and company never bothered to give a firm decision and was delaying the decision forever.