[4] In 1998, Arend joined the cast of Daria[5] as the voice artist for obnoxious flirt Charles "Upchuck" Ruttheimer III.

After the show finished, Arend landed small roles in films such as Super Troopers,[6] where he played a stoner who eats an entire bag of mushrooms to avoid getting caught by the cops after his friend gets pulled over, and Bubble Boy.

[6] He played a man with an intellectual disability in the film The Ringer,[6] and then had a supporting role in the romantic comedy (500) Days of Summer.

[5] Arend previously appeared in the medical drama television series Body of Proof,[6] which aired on ABC from March 29, 2011 to May 28, 2013.

From 2014 to 2019 he was a member of the main cast of the CBS drama Madam Secretary,[6] playing speechwriter Matt Mahoney.