Coordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Elliott Lanam, Justin Fox, Rachael FindlenProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinWritten-By – Bonnie McKee, Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Coordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Elliott Lanam, Justin Fox, Rachael FindlenProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinSitar – Ronobir LahiriSitar [Coral] – Dr. LukeTabla – Aditya KalyanpurViolin [Double] – Gingger Shankar*Written-By – Bonnie McKee, Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Alto Saxophone – Alex FosterArranged By [Horn Arrangement], Tenor Saxophone – Lenny PickettBaritone Saxophone – Ron BlakeCoordinator [Production Coordination] – Irene RichterDrums [Additional] – Steven WolfEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Elliott Lanam, Eric Eylands, Justin Fox, Rachael FindlenEngineer [Horns, Assisted By] – Kenta YonesakaEngineer [Horns] – Dave O'DonnellPerformer – Saturday Night Live Band*Producer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinTrombone – Steve TurreTrumpet – Earl GardnerWritten-By – Bonnie McKee, Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Backing Vocals – Sabina Ddumba, Tensta Gospel ChoirEngineer – Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory BiceProducer, Programmed By – Klas Ahlund*, Max MartinWritten-By – Adam Baptiste, Camela Leierth*, Katy Perry, Klas Ahlund*, Max Martin

Coordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Eric Eylands, Justin Fox, Rachael FindlenProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinWritten-By – Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Backing Vocals – Katy Perry, Max MartinCoordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Mike "Crazy Mike" Foster*, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Elliott Lanam, Eric Eylands, Justin Fox, Rachael FindlenFeaturing [Vocals] – Juicy JProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinVocals [Additional] – Ava JamesWritten-By – Henry Walter, Jordan Houston, Katy Perry, Lukasz Gottwald, Max Martin, Sarah Theresa Hudson*

Engineer – Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory BiceProducer, Programmed By – Klas Ahlund*, Max MartinWritten-By – Katy Perry, Klas Ahlund*, Max Martin

Coordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Eric Eylands, Justin Fox, Rachael FindlenProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinWritten-By – Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Coordinator [Production Coordination] – Irene RichterEngineer – Clint Gibbs, Michael Ilbert, Peter Carlsson , Sam HollandEngineer [Assisted By] – Cory Bice, Elliott Lanam, Justin Fox, Rachael FindlenProducer, Instruments [All], Programmed By – Cirkut*, Dr. Luke, Max MartinWritten-By – Bonnie McKee, Henry Walter, Katy Perry, Lukasz Gottwald, Max Martin

Engineer, Instruments [All], Programmed By – Christian "Bloodshy" Karlsson*, Magnus*, Vincent PontareProducer – Christian "Bloodshy" Karlsson*Written-By – Christian "Bloodshy" Karlsson*, Katy Perry, Mangus Lidehall*, Max Martin, Vincent Pontare

Coordinator [Production Coordination] – Andrew "McMuffin" Luftman*, Scott "Yarmov" Yarmovsky*Engineer – Mikkel Storleer Eriksen*Engineer [Assisted By] – Chris "Anger Management" Sclafani*Guitar [Additional] – John MayerManagement [Stargate Managed By] – Danny D.*, Tim Blacksmith Producer, Instruments [All], Programmed By – Benny Blanco , Stargate Written-By – Benjamin Levin, Katy Perry, Mikkel Storleer Eriksen*, Tor Erik Hermansen

Engineer – Greg Kurstin, Jesse ShatkinEngineer [Additional] – Alex PascoEngineer [Assisted By] – Chris Galland, Delbert BowersMixed By – Manny MarroquinProducer, Guitar, Keyboards, Programmed By – Greg KurstinWritten-By – Greg Kurstin, Katy Perry, Sia Furler

Drums, Piano, Synth, Programmed By – Greg WellsEngineer – Ian McGregor*Written-By, Producer – Greg Wells, Katy Perry

Engineer – Greg Kurstin, Jesse ShatkinEngineer [Additional] – Alex PascoProducer, Bass, Keyboards, Programmed By – Greg KurstinWritten-By – Greg Kurstin, John Mayer, Katy Perry

Coordinator [Production Coordination] – Andrew "McMuffin" Luftman*, Scott "Yarmov" Yarmovsky*Engineer – Mikkel Storleer Eriksen*Engineer [Assisted By] – Chris "Anger Management" Sclafani*Guitar [Additional] – John MayerManagement [Stargate Managed By] – Danny D.*, Tim Blacksmith Producer, Instruments [All], Programmed By – Benny Blanco , Stargate Written-By – Benjamin Levin, Emeli Sandé*, Katy Perry, Mikkel Storleer Eriksen*, Tor Erik Hermansen

Drums, Synth, Programmed By – Greg WellsEngineer – Ian MacGregorKalimba – Jonatha BrookeProducer – Greg Wells, Katy PerryWritten-By – Greg Wells, Jonatha Brooke, Katy Perry