After various senior management and board of director positions in the travel industry Rien became vice president at Real Networks responsible for Europe and LATAM. In 2012 he started as member of the board of directors at NRC Media. Since 2013 he was CEO of NRC Media which was acquired by Mediahuis in 2015. In 2019 Rien switched as CEO to TMG (Telegraaf Media Groep), which was renamed Mediahuis Nederland in the same year.
Mediahuis Nederland is the publisher of the largest newspaper in the Netherlands De Telegraaf, several regional newspapers, magazines, and several online platforms.