Since September 2025, Jannes has been associated with the Dutch-speaking Bar Association of the Brussels Bar. That same year, he joined the team of Claeys & Engels in Brussels, where he works in various branches of employment law at both national and international level. 

In 2025, Jannes obtained his Master of Laws with distinction in 2025 from the Catholic University of Leuven. During his university studies, he specialised in social and tax law.