After signing with the Knights in 2017 as a veteran hooker, Kostjasyn retired mid-season and moved straight into coaching ranks.
Kostjasyn spent two seasons in charge of the Knights NSW Cup side, before moving into an NRL development role in 2020.
2021 saw Kostjasyn promoted to the role of Senior Assistant, working alongside Eric Smith and Willie Peters to support Head Coach Adam O'Brien.
Club Coaching Record
- Win Percentage