Sébastien has a Bachelor of Laws (LL.B., 2016) from Université Laval and a Master of Laws (LL.M., 2019) through a partnership program between Université Laval and Université Paris 1 Panthéon-Sorbonne and was called to the bar in 2019.

A litigator with the firm, he focuses his practice on labour law for a clientele made up of unions, unionized and non-unionized workers, including executives. He also devotes a large part of his practice to workplace group insurance and individual disability insurance cases.

He has acted and is called upon to act before arbitration tribunals, the Tribunal administratif du travail, the Tribunal administratif du Québec, the Superior Court, the Court of Québec and the Québec Court of Appeal.