There were several interviews for the position. First was the interview with the CTO of the company, semi-technical, over the phone. I think it was more to find out whether I was a cultural fit, but also to give me a chance to ask questions. Secondly, they sent me a test online, with 5 simple coding challenges. You can use any language for solutions. They don't make you code a whole app, or solve hard riddles. It is more whether you can code at all. Third interview was in person, lasted about 4 hours, where all the team members of my future team interviewed me one by one. Most of them came prepared with a small challenge for white-boarding.