They call you by email to offer you some slots for an interview. you have to answer and accept, the first is with hr specialist, the second with the team lead manager of the position.
in both cases they seemed nice and very clear in explaining the required job and the task. During the interview they put you at ease, looking friendly but always remaining professional.
once you have passed the various steps you move on to the next steps.
the position seemed very interesting. People seemed also nice.