Karl Martin Sandberg (Swedish: [ˈmǎʈːɪn ˈsânː(d)bærj, - ˈsâmːbærj]; born 26 February 1971), known professionally as Max Martin, is a Swedish songwriter, record producer and singer. He rose to prominence in the late 1990s after making a string of hit singles such as Britney Spears' "...Baby One More Time" (1998), the Backstreet Boys' "I Want It That Way" (1999), and NSYNC's "It's Gonna Be Me" (2000).Martin has written or co-written 23 Billboard Hot 100 number-one songs, most of which he has also produced or co-produced, including Katy Perry's "I Kissed a Girl" (2008), Maroon 5's "One More Night" (2012), Taylor Swift's "Shake It Off" and "Blank Space" (2014), and The Weeknd's "Blinding Lights" (2019). Martin is the songwriter with the third-most number-one singles on the chart, behind only Paul McCartney (32) and John Lennon (26). In addition, he has the second-most Hot 100 number-one singles as a producer, 21, behind George Martin, who had achieved 23 by the time of his death.In early 2013, his single sales were tallied by The Hollywood Reporter to be at over 135 million.