After online application I received an interview invitation with the group leader.
Some days later, I had a set of different interviews, all on the same day and one after the other.
1) interview with a panel of experts where I had to do a small introduction of myself and my previous work, then share a proposal for the job description, and finally a set of Q/A from the experts.
2)interview with the programming experts to review my proposed solution to a technical task they sent to me days before the interview.
3)interview with other members of the institute.
A couple of days later I had an interview with HR and received the official job offer.