I had the luck to participate in a consulting project at Danone, which was really a "course" at my University. They happened to like me and so in the summer I asked for a summer internship. I was asked by their recruiting company to do a numerical and verbal test, as well as a case presentation within a group of peers.
One month went by and they offered me a position as a Trainee. I just had one interview with Human Resources just for them to get to know me: it was really casual, as my project supervisor was also interviewing me and already knew me very well.