Producer: Shellback - Artist: Taylor Swift - Featuring: Kendrick Lamar - Producer: Max Martin - Producer: Ilya - Background Vocalist: Taylor Swift - Background Vocalist: Shellback - Background Vocalist: Kendrick Lamar - Background Vocalist: Ilya - Engineer: Peter Carlsson - Recording Engineer: Michael Ilbert - Recording Engineer: Sam Holland - Recording Engineer: Ilya - Asst. Recording Engineer: Cory Bice - Asst. Recording Engineer: Ben Sedano - Mastering Engineer: Tom Coyne - Mixer: John Hanes - Mix Engineer: Serban Ghenea - Programmer: Shellback - Programmer: Max Martin - Programmer: Ilya - Bass Guitar: Shellback - Acoustic Guitar: Shellback - Drums: Shellback - Percussion: Shellback - Keyboards: Shellback - Keyboards: Max Martin - Piano: Max Martin - Vocals: Taylor Swift - Vocals: Kendrick Lamar