She has appeared in several productions, including AMC's The Killing, HBO's Family Tree, and films like Upstream Color, Alien: Covenant, Pet Sematary, and No Sudden Move.

In addition to her acting career, she has directed, written and produced several films, including 2012's Sun Don't Shine and 2020's She Dies Tomorrow.

In 2015, she co-wrote, co-directed and executive produced the Starz series The Girlfriend Experience, based on the Steven Soderbergh film of the same name,[3] which was released to positive reviews and acclaim.

She also worked with Swanberg on Silver Bullets and Autoerotic, continuing with acting roles in Gabi on the Roof in July, Tiny Furniture,[7] Open Five, and The Myth of the American Sleepover.

[14] In June 2014, Starz announced that they had ordered a 13-episode anthology series of the film The Girlfriend Experience, co-written, co-directed, and executive produced by Seimetz and Lodge Kerrigan.

[3] This came after the film's creator Steven Soderbergh stated: "I think if I were going to run a studio I'd just be gathering the best filmmakers I could find and sort of let them do their thing within certain economic parameters.

[23] She directed She Dies Tomorrow, starring Kate Lyn Sheil and Jane Adams, which was set to have its world premiere at South by Southwest in March 2020, but was cancelled due to the COVID-19 pandemic.

[27] In 2021, Seimetz was announced as the director and an executive producer of The Idol; however, by April 2022 she had left the project amid its creative overhaul, with roughly 80% of the series already filmed.