I got there, the HR told me I have to speak French (my French is basic). Why did they invite me then? ... Anyway they proceeded with an interview. 2 rounds with 2 engineers, the second more senior. Both whiteboard interviews, the first was for about 1/2h - 1h, the second was 2h. The first one was about Python syntax, debugging code. The second was in depth algorithms and data structures. I did well in both, the second engineer seemed very happy with my answers. After a few days I got an answer that they're actually not looking for anyone ... wtf