Short answers, pulled from the story.
James Goddard, an American artist, created the Street Fighter character Dee Jay in 1993. He was the first non-Japanese developer to design a character for the series, marking a significant shift in Capcom's development culture.
James Goddard drew inspiration from real-life kickboxer Billy Blanks to design Dee Jay. He aimed to capture Blanks' high-energy style before Blanks became famous for his Tae Bo fitness program.
Dee Jay appeared in the 1994 live-action film adaptation of Street Fighter. In this version, he was portrayed by Miguel A. Núñez Jr. as a greedy hacker and engineer working for General M. Bison.
In Super Street Fighter II, Dee Jay entered the World Warrior tournament to seek inspiration for his new musical sound. This dual identity as a fighter and a musician added depth to his character beyond mere combat prowess.
Dee Jay is designed to be a Jamaican kickboxer and karateka who is also a recording artist and breakdancer. By the time of Street Fighter 6, he had become a successful musician and part-time actor.