Sundin started his career as a marketing manager at
CBS Associated Records, now part of
Sony Music, in 1989.[13] He was promoted to the marketing director position in 1991.[13] Soon, he left CBS Records and worked with the national radio channel,
Radio City, and Swedish commercial TV channel,
TV4, as an artist manager.[13][12]
In 1998, he rejoined Sony Music Sweden as
managing director.[13][14] Three years later, in 2001, he became the managing director of Sony Music in the Nordic region.[13]
Between 2004 and 2008, Sundin served as the CEO of
Sony BMG after the merger between Sony and
BMG.[13]
In 2008, Sundin joined Universal Music Sweden as the chairman and CEO.[13] At Universal Music, he was a witness in the trial against
The Pirate Bay co-founder,
Peter Sunde, in
Malmö.[15][16] In the same year, he became the first music label executive to partner with
Spotify and thereby opened the door for the streaming platform.[15] His instrumental role in the rise of Spotify is portrayed in the
Netflix drama, The Playlist.[17][18]
In 2010, Sundin signed Avicii to Universal Music, where Avicii in 2011 released his track, "
Levels".[19][20]
In August 2019, Sundin joined Pophouse Entertainment, an entertainment company co-founded by Conni Jonsson and ABBA-member
Björn Ulvaeus, as the CEO.[21][22] Under his tenure, Pophouse Entertainment has among other things acquired the publishing and recording rights of Swedish House Mafia in March 2022, and bought Swedish podcast producer Perfect Day Media.[23][24][25]