Ah You progressed quickly in the sport, being capped by the Canterbury senior team before he had turned 20, and playing at under-age level for New Zealand.

Ah You did not make the step up to Super Rugby level, however, and had not been called up for the Crusaders team by the time he left Canterbury for Connacht.

In that game against Benetton Treviso, Ah You scored his first try for the province and it proved decisive as Connacht won by just two points.

[10] In January 2016, it was announced that Ah You would join fellow Irish province Ulster on a two-year deal from the start of the 2016–17 season.

He made his Premiership debut against Saracens on 5 April 2019 after returning to full fitness and remained a key asset in Falcons' 2018-19 campaign.

In January 2014, Ah You was one of seven uncapped players named in Ireland's extended 44-man squad for the upcoming Six Nations by head coach Joe Schmidt.

Ah You was named on the substitutes bench for the first test of the series in Resistencia and came on as a second-half replacement for Mike Ross as Ireland came out 29–17 winners.