First breaking through as a performer with the Los Angeles comedy troupe The Groundlings, Rudnitsky garnered widespread attention for his brief stint as a cast member on the NBC sketch comedy series Saturday Night Live during the show's 41st season between 2015 and 2016.

[8] On August 31, 2015, it was announced that Rudnitsky would join the cast of Saturday Night Live as a featured player for the show's 41st season.

[11] He has also done impressions of Wolf Blitzer, John Mayer, Martin Scorsese, Tom Cruise, and Vladimir Putin (in a dress rehearsal sketch on the season 41 episode hosted by Donald Trump), while also doing a Dirty Dancing sketch for Weekend Update, which was seen as one of his high points for the season.

He starred alongside Jane Lynch and Genevieve Angelson in the NBC pilot Relatively Happy, which was not picked up.

[15] In March 2020, Rudnitsky was cast as Mike Devries in the musical comedy-drama television series The Big Leap, which premiered on Fox on September 20, 2021.