Apart from sending a cover letter talking about my ambitions and my interest on the firm, I also had a brief interview with one of the collaborators. Here I had to answer to some general questions, about my personal background and laboral experience.

Was contacted via phone call and email and ended up setting a date for face to face interview. There was a 8-9 strong interview panel (including the HR). This was a technical viva round. After clearing that round there is a written technical round followed subsequently by HR interview.