[1] Weitz is also a writer, executive producer, and director of the Amazon Prime Video dramedy series Mozart in the Jungle.

Weitz is the grandson of Czech-born agent and producer Paul Kohner and actress Lupita Tovar on his maternal side.

[6] Weitz' paternal grandparents escaped Nazi Germany, where his grandfather had been a successful textile manufacturer, and family intimates of Christopher Isherwood and Marlene Dietrich.

In 1999, he and Chris directed and produced American Pie, which was written by Adam Herz, and became a major box office success.

In 2002, the Weitz brothers co-wrote and co-directed About a Boy, the Hugh Grant film based on the book by Nick Hornby.

[19][20] The film was originally set up at New Line Cinema with Robert De Niro producing, and the main character as an American.

[6] Weitz has written and directed the well-received romantic comedy In Good Company and the political satire American Dreamz, which faced mixed reviews.

He has also directed an adaptation of Darren Shan's young adult novel Cirque du Freak called The Vampire's Assistant.

Weitz has written a number of plays, including Roulette, Privilege, Show People and Trust, all of which have been produced Off-Broadway in New York City.

[36] Trust starred Zach Braff, Bobby Cannavale, Sutton Foster, and Ari Graynor, and was directed by Peter DuBois at Second Stage Theatre.