His first short film I Shall Fear was shown at the 1999 Victoria Independent Film and Video Festival. Put That Away was screened as part of the Digital Gun Awards in Toronto (2003). Istvan’s first feature was the indie horror film The Modern Things (2003).
In 2015, his one-act play, The Atomic Tradition, premiered in Toronto under the direction of Sophie Ann Rooney and featuring Oluniké Adeliyi and Alana Pancyr.
In 2016, he directed Our Soul’s production The Ties That Bind for both the Hamilton Fringe Festival and at Theatre Passe Muraille as a special presentation for World Suicide Prevention Day 2016.
Istvan was also a senior writer for Mooney on Theatre from 2014 to 2019.