Career
Kostomarov began skating at the age of nine and a coach put him in ice dancing at eleven. Kostomarov began competing with Tatiana Navka during the 1998-1999 season. They were coached by Natalia Linichuk.
Linichuk then dissolved the team and paired Kostomarov with Anna Semenovich.
He competed with Semenovich during the 1999–2000 season. In mid-2000, Kostomarov called Navka and asked to skate with her again.
They were coached by Alexander Zhulin in New Jersey. Navka/Kostomarov retired from competition after the Olympics but continue to skate in shows together.
Kostomarov has skated with celebrity partners in Russian ice shows such as Ice Age.
(with Navka).