Rocket Fuel Machine Learning Research Scientist interview questions

Got an email from the recruiter and then did not hear anything from them until a month later. Than I had 1 phone interview and another "phone interview". The second did not call me but chatted with me on collabedit. It was a really really strange approach. I wrote the code very easily. Then he said you do not need to put parentheses in Python. I said this is just for clarification and making it more readable. He said if you have any questions write it here for me. In the end He said "you did a great job and I will set up another interview for you". The next day I received a rejection email.