Henry Russell Walter (born April 23, 1986), known professionally as Cirkut, is a Canadian record producer and songwriter. He has co-produced and co-written for Rihanna, Kanye West, Ava Max, Pitbull, Katy Perry, Miley Cyrus, The Weeknd, Britney Spears, Jessie J, Kesha, Shakira, Nicki Minaj, and B.o.B, and songs he has written and produced include the "Billboard" Hot 100 No. 1 singles "Part of Me", "Roar" and "Dark Horse" by Katy Perry, and "Wrecking Ball" by Miley Cyrus. His production credits on The Weeknd's album "Starboy" won him the 2018 Grammy Award for Best Urban Contemporary Album. His most recent collaboration was on Kanye West's 10th studio album "Donda."