I had a first 15 minute skype interview with the CEO and some of the employees that was non technical (we only discussed what they do and what were my skills). After a few days they invited me for an interview on site. There I had three interviews: a short one with some logic problems, a second one that was longer with a quite difficult coding exercise and then questions about the skills on my CV / what I learned at school, and a third one with the CEO and the second interviewer that was more to show me what the company does and what I would be doing there as an intern. Overall I spent a few hours there. The interviewers were all really nice and helped me get through the problems as I was trying to show that I understood what was asked and I was going in the right direction. For the coding exercise, I had brought my own laptop, they let me choose my favorite programming language (Python). I heard back from them a few days letter with an offer that I accepted. Great 4 month experience there with an amazing team, working on a really cool product. I would definitely recommend this company to a friend, good luck with the interview !