Koster is a graduate of the University of Manitoba, and Concordia University in Montreal, where he graduated with distinction in the Fine Arts (Film Production) Program in 1984.

Koster's diverse career in the industry includes work as a film technician, film liaison officer, producer and director. His documentary A KIND OF FAMILY, directed for the National Film Board of Canada, was nominated for a 1992 Genie Award for "Best Short Documentary".

In 1997, he became an Executive Producer at Credo Entertainment. His credits include the television movie NIGHTS BELOW STATION STREET (CBC/Lifetime) and all 52 episodes of the television series WORLD'S GREATEST SPAS (WTN).

Koster left Credo in the summer of 2000 to concentrate on the development, production, and marketing of documentaries, drama, and factual entertainment. Production projects include HEAD OVER WHEELS (WTN), THE END OF EVOLUTION (Discovery Channel Canada) and ME, MY BROTHER, AND MY FATHER'S VAN GOGH (CBC–Witness), and many others.