Fuchs has been acting since he was seven years old, making his debut at Lincoln Center in the play Abe Lincoln in Illinois with Sam Waterston. Fuchs has also guest-starred on Cosby, The Sopranos, The Beat, Law & Order: Criminal Intent, Law & Order: Special Victims Unit, Ed, and All My Children. His first feature film role was as Marvin in the 1996 movie Flipper, co-starring Elijah Wood. In 1998 he appeared in two movies, Louis & Frank and Jane Austen's Mafia!. Fuchs also starred in 2003 film The Hebrew Hammer, co-starring Adam Goldberg.

In 2004, Fuchs took the role in Winter Solstice. Fuchs wrote, produced and starred in the 2006 short film Pitch, which made its premiere at the 2006 Cannes Film Festival. He next appeared in Holy Rollers, a movie inspired by actual events in the late nineties when Hasidic Jews were recruited as mules to smuggle ecstasy from Europe into the United States. He played a brother of Justin Bartha's character, alongside Jesse Eisenberg and Ari Graynor.

In 2012, Fuchs' original TV movie musical, Rags, was broadcast on Nickelodeon. The film, which Fuchs co-wrote with Hillary Galanoy & Elizabeth Hackett with Billie Woodruff directing, was a revisionist take on the Cinderella tale, starring Keke Palmer and Max Schneider. The film received 3.5 million live viewers.

His script Pan was listed on Hollywood's 2013 Black List, and was made into a 2015 film, which was a critical and box office failure.

Fuchs co-wrote the 2017 film Wonder Woman with Zack Snyder and Allan Heinberg. In 2016, Warner Bros. hired Fuchs to write the script for a Lobo feature film, and a film adaption of the video game Minecraft.