Career
He is the current head coach for Oulun Kärpät of the Finnish Liiga. He is notable for becoming a pro coach at a relatively young age, having only played for a couple of seasons" worth of junior hockey semi-professionally before turning to coaching. Marjamäki was named as a Team Finland assistant coach under Erkka Westerlund at the 2014 Winter Olympics in Sochi, Russia.
Marjamäki was revealed as the next head coach of the Finnish national team in August 2015, succeeding Kari Jalonen.
His tenure will begin after the 2015-2016 season.