[2] He and his writing partner Micah Fitzerman-Blue wrote the script for A Beautiful Day in the Neighborhood about Fred Rogers which landed on the Black List in 2013.

[3] After a nearly 10-year process, it was released in 2019, starring Tom Hanks,[4] Chris Cooper, Matthew Rhys, and Harpster himself in a small role.

[citation needed] Since 2019 he has played NASA Mission Controller Bill Strausser in the Apple TV+ alternate history series For All Mankind, created by Ronald D. Moore, Matt Wolpert and Ben Nedivi.

Painkiller is a dramatization of the birth of the opioid crisis and stars Matthew Broderick, Uzo Aduba, Taylor Kitsch, Dina Shihabi, and West Duchovony.

It is based on the reporting work done by Barry Meier for the New York Times and Patrick Radden Keefe for the New Yorker.