Chun worked on The Simpsons for six years (2005–2010) and on The Office for three years (2009–2012), advancing to co-executive producer on both series.
During the 2012–2013 season, Chun worked as a consulting producer and writer on the third season of the ABC comedy series Happy Endings.
Chun’s writing has also appeared in New York, 02138, Vitals, and TheNewRepublic.com, and The Huffington Post.
Chun is a trustee of The Harvard Lampoon and serves on the Sundance Institute Episodic Advisory Council. Chun has appeared as speaker and mentor at institutions including the University of Pennsylvania, the Austin TV Festival, FAMU in Prague, the Seoul Digital Forum, the Paley Center, the Sundance Institute, and Harvard University.
Chun was a head writer on The Office and received two Primetime Emmy Award nominations for the series, in 2010 as supervising producer and in 2011 as co-executive producer. Chun was among the writers nominated for Writers Guild of America Awards for his work on The Office.
He was named one of Variety's 10 TV Scribes to Watch in 2015.
While Chun was an executive producer and co-executive producer on Speechless, the series won the 2017 Television Critics Association Award for Outstanding Achievement in Youth Programming.