It took almost 2 months to get through the entire process. They went to my university during a recruiting event and took our emails and some personal data, pretty normal information. The next weeks, they sent an online test with over 120 questions, that took over 1 hour to solve. All those questions were behavioral, nothing technical was asked.
Then they sent me the same test again, and again, and again. I had to solve it 5 times, exactly the same long test. After that, I was called to an onsite, in what the call "The Enel Day". It was in a nice hotel with amazing food, and they gave us small presents (like power banks, for example). That day we went through 3 different rounds of interviews, 1 in group and 2 personal. The group interview has about solving a problem (that had no clear answer) in groups of 8 people.
In the personal interviews, they asked about our academic life and a bit about ourselves. That part was with an human resources girl. After that, we had an interview with one of the engineers of the company, which was more technical.
The day started at 7:00am, and my last interview was over al 6:00pm