WoW Insider reports based on multiple sources. Street had previously held the position of lead systems designer on World of Warcraft at Blizzard, a job that gave him visibility as a franchise spokesperson and one that he vacated over five years later in 2013.
Prior to his time at Blizzard, Street spent nearly a decade at Ensemble Studios as a designer on the Age of Empires franchise. Street was the lead designer on Age of Empires 3, the last version of the game Ensemble independently developed before being shuttered in 2009.
Riot Games has only one game under its belt, but it's a big one: the wildly successful (and popular among lead designers) League of Legends, which launched in 2009.