Short answers, pulled from the story.
Dee Jay was created by American designer James Goddard for Super Street Fighter II, released in 1993. Goddard chose the name as a variant of his own nickname, DJames, making Dee Jay the first Street Fighter character designed by an American.
Dee Jay is based on kickboxer Billy Blanks, drawn from his role as a villain in the film The King of the Kickboxers. Designer James Goddard suggested Blanks as an inspiration when the Japanese development team asked for more character ideas, describing Blanks's athleticism as ideal for a high-flying fighting style.
The original design had the word "MANTIS" on Dee Jay's pants, but his left-facing sprite was a mirror image of his right-facing one, which reversed the letters N and S. The team replaced "MANTIS" with "MAXIMUM" because it read correctly in both orientations.
Miguel A. Nunez Jr. played Dee Jay in the 1994 live-action Street Fighter film. In the movie, his character was reimagined as a greedy hacker and engineer working for General M. Bison, replacing the musical background he had in the games.
Dee Jay debuted in Super Street Fighter II (1993) and later appeared in the console versions of Street Fighter Alpha 3 (1998), Street Fighter: The Movie, Super Street Fighter IV, and Street Fighter 6. He was absent from Street Fighter IV, though audio files from that game contained an announcer calling his name, indicating early development work.
Dee Jay has received mixed reception. Rocky Mountain News called him probably the best of the four new characters in Super Street Fighter II, and professional player Keith Stuart ranked him as his second favourite Street Fighter character. However, critics including those at Paste and Eurogamer have called him one of the series' least sensitive stereotypes and part of a broader pattern of problematic black character portrayals in 1990s games.