It was a group interview, an assignment was sent a week before, and we were called only if we had passed that. There were 12 of us, and were split into 2 teams. 4 assignments in total, none really related to any particular skill or product of Tenaris. All they wanted to judge was how we worked in teams, and how good were we at pitching ideas. They also wanted to know how would we negotiate. Halfway through the process, the interviewers stopped really paying much attention to one of the groups, which could be observed clearly- seems they already made up their minds. At the end, each member was asked to speak about himself/herself for about 2 minutes.