Vasseur and Hamilton's talents combined in the 2006 GP2 season, and the pair will work together again from 2025 onwards in the hope of recreating those championship-winning ways.
GPFans spoke exclusively with an insider who revealed just how close the two were, and how the team dynamic worked when two of modern F1's most influential players previously shared a garage before their time at the top.
Frederic 'Fifo' Guyot was Hamilton's race engineer in GP2 at ART GP and has similarly undergone an upward journey of his own, now managing ART's Formula 2 team.
Guyot's first season in GP2 coincided with Hamilton's, and he remembers, "It was from a young perspective on my side at that time, but they [Vasseur and Hamilton] were really close.
"Fred had a very good relationship with McLaren, which probably helped to have Lewis...
"Lewis was really respectful and really nice with the team.
"At the moment, I don't speak with him at all, and I think he's on another planet.
"But at that time, he was a really good guy in the team; everyone liked him.
"The team was pushing for him, and we had a really good relationship.
"We had dinner with him; he was spending a lot of time with the team, and Fred and Lewis had a really friendly relationship."
Although Vasseur is now Ferrari's team principal, he created ART GP alongside Nicolas Todt, son of Ferrari legend and former FIA president Jean Todt, in 2005.
Guyot continued to say, "Fred is still very close, spending time with us.
"He has always had a good talent for identifying the best young drivers.
"Many times, we got the best driver we could have, and he's still in relation with ART because it's his company.
"He likes young drivers and the junior categories, so he's still really following it, even if he's really busy with Ferrari."