Demian graduated from the Netherlands Film Academy in 2021 with De Pinpas, which was awarded best graduation film of the year by CILECT and won several awards at international film festivals. The film also earned him a nomination for the Zilveren Krulstaart award. After graduating, he wrote the encounter Kooi and Film Fund short Inhumaan, both of which premiered at the Dutch Film Festival. Together with screenwriters Dajo Leunge and Thijs Bouman, he also developed the youth series De Achterblijvers in 2024, which was created in collaboration with BNNVARA and has since been realized.

Demian is currently working on the screenplay for Telefilm de padvinders and is in the pre-production phase of Film Fund short De Floor is lava, for which he will also take on the role of director. His work often revolves around characters who balance between childlike innocence and the harsh realities of adult life. He enjoys addressing poignant and social themes with playfulness and humor.