** I feel they just wanted to collect new ideas about how to solve their technical problems, without actually hiring anyone ... ** The HR approached me, I did not apply online. After meeting with the hiring manager, I was invited for onsite interview very quickly. ** In the onsite interview they literally asked me to solve the specific problems they were facing; they opened a notebook showing their actual problem and asked me all possible ideas I could think of to solve that problem.! ** The 1-2 other technical interviews also went pretty much the same way, asking for all solutions I could think of, theoretically. In my opinion these rounds went perfectly as I was able to literally answer all questions even help create a ML model on their real data with acceptable accuracy. ** There was a coding challenge at the end which was terrible. I mean the coding question was reasonable but the interviewer was not! Any time I asked a question or made a comment which seemed wrong, the interviewer would quickly take notes on her computer. This was frustrating as she made it very obvious that she was taking notes on my mistakes! ** And after a few days I received a call from the HR, and as I expected, he said they did not move forward. He said they would like to stay in touch for future roles ... but honestly I don't want to get involved with them anymore.