Jeff joined Riot in 2007 as one of their first interns and was one of the original 11 developers who began the development of League of Legends. He helped create the original design documents for League of Legends' core gameplay, user interface and platform as well as codesign the original 22 champions alongside Colt 'Ezreal' Hallam and Steve 'Guinsoo' Feak. Jeff would later become the Product Owner on Skins, Champions, Maps, and Gameplay on League of Legends before moving off to Research and Development to start the development of Legends of Runeterra.
- The champion was named after him.
- He was one of Riot's founding interns.