Henry Russell Walter, known professionally as
Cirkut, is a Canadian record producer and songwriter. Described by
The Hollywood Reporter as record producer
Dr. Luke's "right-hand man and main production partner", he has co-produced and co-written for
Jessie J,
Britney Spears,
Kesha,
Rihanna,
Shakira,
Nicki Minaj,
B.o.B,
Lil Wayne, and
Taylor Swift, including the
Billboard Hot 100 No. 1 singles, "
Part of Me", "
Roar", and "
Dark Horse" by
Katy Perry, and "
Wrecking Ball" by
Miley Cyrus.