Marwan has worked in Saudi Arabia since 2007. He first joined the law firm Dewey LeBeouf as a full-time American lawyer. Later, he joined ABB as head of legal and compliance for the subregion of Saudi Arabia, Kuwait, Bahrain, and Yemen.
In 2011, he joined the Riyadh office of the US firm Jones Day. After a couple of years, he moved to private practice as deputy general counsel of Mawarid Holding Company. Currently, he is of counsel with AKA Law.