[2] His father is a Dutch musician, and his mother an English pop singer who was a member of the musical duo Spooky and Sue [nl].
[1] Jansen played youth football for AZ, Ajax, Haarlem and Telstar, but retired due to a knee injury before making his professional debut.
[7] He moved to AZ to work as a coach in July 2018,[8] before being promoted to manager in December 2020, on a contract until the end of the season.
[4] He was dismissed on 17 January 2024 after narrowly avoiding a KNVB Cup upset against amateur club Quick Boys.
[10][11] He debuted with a 5–0 victory over The New Saints in the 2024–25 UEFA Champions League qualifying phase at Groupama Aréna in Budapest on 23 July 2024.