Since college the scientist has had a faultless career:  "in the final year of my 'A' levels I knew that I wanted to go to an engineering school, I thought the best way would be a preparation class since it allows you to join any establishment (you need to have a good ranking afterwards).  I took the MPSI class (Maths, Physics and Engineering Sciences) because I was interested in the subjects and they corresponded to my study project".  Two intensive years, but ones he doesn't regret:  "the work is so substantial that you quickly learn how to organise yourself, how not to waste time and then the level for science is relatively high so engineering school isn't that much of a worry, you can spend more time on projects."
Alexis has just successfully completed the written examination for his Research Masters that he is undertaking at the same time as his third year at ESAIP: he ranks 2nd.  Undoubtedly the preparation class has a bearing on his success.