After training as a primary school teacher, the Swiss actor studied at Konservatorium Bern before moving to Jürgen Flimm's Thalia Theater in Hamburg. There he got to know Robert Wilson, who had a profound influence on his artistic development (‹Black Rider›). Stefan first appeared in front of the camera in 1993. As the lead character in the TV mini-series ‹Der Schattenmann› directed by D. Wedel, Stefan became known to a wider audience and received various awards, including the Adolf Grimme Prize and Telestar. His roles range from dramatic material such as ‹Der Verdingbub› (M. Imboden) and ‹Jagdzeit› (S. Boss) to children's films ‹Pettersson und Findus› (A.S. Ahadi) and comedies like ‹Papa Moll› (M.F. Hendry) and in 2022 ‹Die goldenen Jahre› (B. Kulscar). Stefan manages to remain faithful to the music and theatre arts. In Basel, he played Zaza in ‹Käfig voller Narren› (M.G.
Berger) in 2018 and Frosch in ‹Rache der Fledermaus› at Casinotheater Winterthur (S. Huber) in 2019. This was followed in 2020 by ‹Frühlingsstürme› (B. Kosky) at Komische Oper Berlin. Stefan has also been working as a photographer and visual artist since 2006.