First part of interview was brief phone interview with recruiter where I was asked about my previous roles and some HR questions. After that I was given couple of technical questions regarding my Python experience. Next step was a call from Lead engineer where I had solve couple of their past issues and show my experience in the field. After that I had another call with Principal Engineer about my technological fit in the company. Next was onsite visit with 4 more interviews, 3 technical and one HR. After all those I was given a call by CEO to have final chat. Overall whole interview process was very interesting, challenging (in good way) and quite short (given all the steps). All people were extremely friendly and easy to speak to.