He is a six-time Grey Cup champion as an assistant coach, having won three times with the Calgary Stampeders, once with the Winnipeg Blue Bombers, and twice with the Argonauts.

[2][3] Costanza first entered the CFL as a receivers coach for the Calgary Stampeders in 2008, as part of John Hufnagel's inaugural staff which reunited the pair after first working together for the New Jersey Red Dogs.

[6] On November 27, 2019, it was announced that Costanza and the Stampeders had decided to part ways, although it was reported that he could not be retained due to the newly implemented football operations salary cap imposed by the league.

[6][7] On January 21, 2020, it was announced that Costanza had joined the Winnipeg Blue Bombers to serve as the team's running backs coach.

As the pass game coordinator in 2024, Costanza worked with three different starting quarterbacks as the team finished 10–8 and won the 111th Grey Cup.