Joass represented Tasman Mako in the Mitre 10 Cup and has captained the Tasman Mako seven team, in 2017 he made his All Blacks Sevens debut in Sydney that same year. Joass played as New Zealand won the Gold Medal at the 2018 Commonwealth Games and scored a try in the 2018 Rugby World Cup Sevens Final in San Francisco as the All Blacks defeated England to win the title.