Henry Walter, known professionally as Cirkut, is a Canadian music producer and songwriter. He has co-produced and co-written songs for artists sich as Britney Spears, Ke$ha, Rihanna, Katy Perry, Nicki Minaj, B.o.B, Lil Wayne, Ava Max, and Taylor Swift.
Walter was raised in Halifax, Nova Scotia and moved to Toronto in 2004. He co-produced the Britney Spears song "Mmm Papi" which appeared on her 2008 album Circus. He sent it as an instrumental track to Kobalt Music Group via their attorney Chris Taylor, where songwriter Nicole Morier began using it to write with Britney Spears.
Walter opened Dream House Studios in Toronto. He then relocated to Los Angeles, California. He co-produced "Part of Me", the title song to Katy Perry's 2012 concert film Katy Perry: Part of Me. Walter was also responsible for producing and co-writing The Weeknd's track "High for This". He recently co-produced and co-wrote 9 songs on The Weeknd's album Starboy.