Producer: Dr Luke - Artist: Katy Perry - Producer: Max Martin - Producer: Cirkut - Mixer: Serban Ghenea - Engineer: Peter Carlsson - Engineer: Clint Gibbs - Engineer: Sam Holland - Engineer: Michael Ilbert - Asst. Recording Engineer: Eric Eylands - Asst. Recording Engineer: Rachael Findlen - Asst. Recording Engineer: Justin Fox - Asst. Recording Engineer: Elliot Lanam - Asst. Recording Engineer: Cory Bice - Mix Engineer: John Hanes - Vocals: Katy Perry - Programmer: Dr Luke - Programmer: Max Martin - Programmer: Cirkut - Drums: Steven Wolf - Production Coordinator: Irene Richter - Horn: Lenny Pickett - Engineer: Dave O'Donnell - Asst. Recording Engineer: Kenta Yonesaka - Tenor Saxophone: Lenny Pickett - Trumpet: Earl Gardner - Alto Saxophone: Alex Foster - Trombone: Steve Turre - Bari Sax: Ron Blake - Remixer: Cash Cash