In 2010, Joo was selected for the South Korean junior national short track speed skating team and won the gold medal in the men's 3000 metre relay at the 2010 World Junior Short Track Speed Skating Championships held in Taipei, alongside Noh Jin-kyu and Park Se-yeong.

Joo captured silver in the team pursuit race at the 2013 World Single Distance Championships held in Sochi, alongside Olympic champion Lee Seung-hoon and Kim Cheol-min.

[2] Joo also achieved four podiums, including a silver in the mass start race, in the 2012–13 World Cup series.

[3] The South Korean pursuit team for the 2014 Olympics consisted of Joo, Lee Seung-hoon and Kim Cheol-min.

[4] South Korea eliminated Russia in the quarterfinal, which advanced them to face reigning Olympic Champion Canada in the semifinal.