Jack transitioned into coaching with Peterborough United in 2015, spending two years in their youth academy. He returned to West Ham United in 2017 to coach their U18 and U21 teams and then moved to the United States in 2019 to serve as the head coach for Atlanta United's U17 team. In 2020, Jack was elevated to coach Atlanta United 2, the MLS Reserve team, where he led them to the highest USL Championship standing in club history. Prior to his appointment as SSA Swarm FC's USL 2 head coach, he was the head coach for Huntsville City FC from 2023 to 2024.

Jack had a stellar playing career, where he played for English Premier League side, West Ham United, from 2006-2014. He went on loan to Bournemouth in 2013 and to Wigan in 2014. He retired from professional soccer in 2016 after spending the 2015 season with Peterborough United. Jack earned 15 caps with Wales National Team.