Henry Russell Walter, known professionally as Cirkut, is a Canadian record producer and songwriter. He has co-produced and co-written commercially successful singles, often in tandem with American record producer Dr. Luke and Swedish producer Max Martin since 2008. His credits include songs and albums for prominent artists including Katy Perry, Becky G, Ava Max, Nicki Minaj, R. City, the Weeknd, Kesha, Ciara, Pitbull, Britney Spears, Ne-Yo, Rihanna, Adam Lambert, B.o.B, Marina and the Diamonds, will.i.am, Jungkook, G.R.L. and Juicy J, among others.

"Part of Me" is a song by American singer Katy Perry, released as the lead single from Teenage Dream: The Complete Confection. It was written by Perry and Bonnie McKee, with production and additional writing by Dr. Luke, Max Martin, and Cirkut. The song was not included on the original edition of Teenage Dream because Perry felt that it did not fit the composition of the album. A demo of the song leaked online in late 2010, amid speculation that the lyrics were directed to the singer's ex-boyfriend Travie McCoy. "Part of Me" was re-worked and officially released on February 13, 2012, through Capitol Records with artwork by art director Gavin Taylor and photography by Mary Ellen Matthews.