Songfacts®:

• Charli XCX's first collaboration with Troye Sivan was her nostalgic anthem "1999." A year later, the pair reunited for a futuristic new song; "2099" travels exactly 100 years from their previous hook-up.
• Lyrically, the song is a sweary, braggadocios track sung primarily by Charli XCX. She spends much of her sole verse touting her superiority over a competitor. The songstress is joined on the chorus by Sivan.
  
  I'm Pluto, Neptune, pull up, roll up, future, future, ah
  
  The pair will continue to be top of the game well into the future.
• Charli explained to Apple that after they'd recorded "1999," she suspected Sivan "wanted to get a little bit weirder than we got," as she'd heard him mention he was into her experimental mixtape Pop 2. She added: "After '1999' came out, I hit him up again and said, 'Should we just go there? Should we just go out of space? Like, let's do a weird moment.' And he was like, 'Yes, let's do it.'"
• The song was produced by:
  
  A.G. Cook, who also served as executive producer on Charli.
  
  Ö, who is a Montreal producer also known as Nömak. His other collaborations with Charli include her Christine and the Queens hookup "Gone."
• The video, directed by duo Bradley & Pablo, takes place off the coast of an island. The clip shows Charli and Troye driving jet skis around while showing off a variety of striking stunts. Troye's skills (likely with the help of a stunt double) are especially impressive practically defying gravity.
  
  The visual is Charli's fourth collaboration with Bradley & Pablo following "Vroom Vroom," "5 in the Morning" and "Blame It on Your Love ."