Jay Kyburz was one of the first team members hired to work at Irrational Games' Australian studio (later known as 2K Australia). His first job at Irrational was Lead Artist during development of Freedom Force. He faced many challenges due to the fact that there were only 2 other artists working on the project at the time that he was hired, and neither of the two had worked in games before. The team had to build the game essentially from scratch, because at the time they had no level editor or tools to import assets into the Gamebryo Engine. As a result, Jay Kyburz did a lot of coding with MAXscript.
Later he became Lead Level Designer of Tribes: Vengeance, developing four single player levels and two multiplayer maps for the game. He was also the Lead Designer of the Swat: Stetchkov Syndicate expansion for Irrational's Swat 4.
During production of BioShock, Jay Kyburz was part of the art team. He was involved in creating the Arcadia, Farmer's Market, Point Prometheus and Proving Grounds levels. Some time during production of BioShock, Jay Kyburz moved to a different team focusing on 2K Australia's next game project. He eventually left to form his own independent developer, called Iron Helmet, and released the free, browser-based multiplayer strategy game Neptune's Pride.