German-born and raised, Marx began his career in theatre in Stuttgart, Germany. After an 8 year stint in many theatre productions, he graduated to being a writer/producer and moved to Berlin to stage theatre productions and act in movies and TV.

In 2010 he founded the production company Ente Kross Film and co-produced the feature film Die Tochter (2017) which was shown at the International Filmfestival in Berlin. But what changed his life was co-producing the romantic comedy Männer zum Knutschen (2012) which won awards and remains in worldwide distribution, but, most importantly, was screened at a film festival in San Francisco. Several years later he produced the German short film award-winning Das Phallometer (2013), which brought him back to San Francisco to present the film at the Frameline Film festival.

He relocated to San Francisco in 2017. He can be seen in the documentary Gay Chorus Deep South (2019) which will have it's world premiere at the Tribeca Film festival in 2019. Besides being an actor and producer, he is also a tour guide of his city.