Weitzman is a regular performer at the Upright Citizens Brigade Theater in Los Angeles. He has appeared in television and film projects such as Burning Love, The Sarah Silverman Program, Childrens Hospital, Role Models, School for Scoundrels, Love, and Ocean’s Thirteen. He was also on the short-lived MTV show Zach Stone Is Gonna Be Famous as the title character’s best friend, Greg LeBlanc. In 2009, he starred in the Say Anything music video for “Shiksa (Girlfriend)”. Alongside Wittels, Weitzman made his directorial debut in 2014 with the short film The Badger’s Promise, which the pair also co-starred in as fictionalized versions of themselves. He co-starred as the servant Garfield in the Comedy Central show Another Period, and appeared as Jeff in Silicon Valley, as Ruby in Netflix’s Love, and as Lorne Michaels in A Futile and Stupid Gesture.

On July 23, 2019, multiple news outlets picked up the story of a seemingly pristine Double-Double from In-N-Out Burger found on the streets of Queens, New York City, over 1,500 miles from the nearest In-N-Out. Several NBC affiliates specified that the burger was “not Armen style”, referring to Weitzman’s topping order of half grilled onions, half raw onions, which was popularized through Doughboys.