A graduate in industrial relations and the faculty of law at the Université de Montréal and with a certificate in economics, Denis practices primarily in labour law, administrative law and professional disciplinary law. Partner at the firm, he specializes in grievance arbitration, individual employment law, workplace health and safety and legal issues affecting the arts community.

In addition to regularly providing training and representing clients before the various administrative tribunals, Denis regularly represents clients before the Superior Court and the Court of Appeal. In winter of 2014, Denis successfully represented a client in the Dionne case before the Supreme Court of Canada, involving the rights of precarious workers and the right to equality.

Denis participated in the creation and publication of the Guide des meilleures pratiques en arbitrage de grief, prepared by the liaison committee between the Barreau de Montréal and the Conférence des arbitres. Today, he is the president of the committee in charge of updating the guide. He has also been the vice-chair of the Quebec section of the Canadian Bar Association.