[1] He represents the electoral district of Saint-Jérôme as an independent, and was originally elected as a member of the Coalition Avenir Québec.
Chassin worked as a researcher and economist with the Montreal Economic Institute, in November 2010 to March 2017.
Prior to this, he was an economic analyst at the Quebec Employers Council (CPQ) and an economist at the Centre for Interuniversity Research and Analysis on Organizations (CIRANO).
His interest in public policy issues goes back to his university days during which he collaborated with the Quebec Federation of University Students (FEUQ), with the Conseil permanent de la jeunesse and with Force Jeunesse.
[5] In September 2024, Chassin announced he was resigning from the Coalition Avenir Québec party and would sit the remainder of his term as an independent.