G-rex grew up around Detroit and graduated from Plymouth High School. In 2013, Sweeney started making music while attending Western Michigan University where he studied marketing. After graduating, he wanted to focus more on music production and enrolled in ICON Collective in Los Angeles, California.  In October 2018, G-rex released his debut EP RIFToff Liquid Stranger's label WAKAAN. Sweeney has remixed a number of songs such as "Deep Down Low" by Valentino Khan, "Tell You Why" by Dion Timmer, "Rebels" by Black Tiger Sex Machine and Kai Wachi, and "Witch Doctor" by ATLiens.  G-rex's song with PEEKABOO "Babatunde" is named after their Postmates driver who delivered PEEKABOO tacos.