After high school, Marderosian worked for advertising agencies and an art supply company, where he prepared paste-ups and mechanicals for catalogs.

After an early-career rejection, Marderosian "finally [got] his foot in the Disney door in 1990,"[3] working on merchandise related to Jessica Rabbit.

[6] In 2007, Marderosian designed and successfully marketed his own collection of children's stuffed animals called "Angels from the Attic.” Each toy set included a related story book.

Their children’s media company, Big City Publishing, offered to provide the program free of charge to Public-access television cable TV stations.

[6] In 2013, the Boston/New England Chapter of the National Academy of Television Arts and Sciences nominated "Drawing with Mark" for a Regional Emmy award in the Children’s/Youth category.