Career
Representing the Soviet Union, he is the 1992 World Junior silver medalist. Following the dissolution of that country, he began to compete for Latvia. He placed 20th at the 1992 Winter Olympics for that country.
He competed at five World Championships (1992, 1993, 1997, 2000 and 2001).
Kostin currently works as a coach. He is the director of skating at the Yarmouth Ice Club in Kingston, Massachusetts.
He has coached Michelle Boulos. He is an international technical specialist for Latvia.