Since graduating from the National Theatre, Joab has appeared in several films and television, including City Homicide, Rush, My Year Without Sex, 10 Terrorists, and Conspiracy 365.
In 2011, Joab successfully auditioned for the recurring role of Ajay Kapoor in the soap opera Neighbours.
The actor has since appeared in SBS miniseries Better Man, feature films Lion (2016) and Hotel Mumbai (2018), and television series Pine Gap, The Hunting, Upright, and Jack Irish.
[2][3] Joab, who spent his childhood imitating the voices of characters he watched on television, did not need to undergo accent training.
[3][4] 2011 saw Joab cast in Big Mamma's Boy and Winston Furlong's Taj, alongside his future Neighbours co-star Coco Cherian.
"[10] Joab left Neighbours at the end of his contract in May 2013 to pursue acting work in Los Angeles.
[17] That same year, Joab played the lead role of Amir Kapoor in the Sydney Theatre Company (STC) production of Disgraced.
[15] He also appeared in the feature films Upgrade directed by Leigh Whannell,[21] and Hotel Mumbai, alongside his Lion co-star Dev Patel.
[15] In 2019, Joab appeared in the four-part SBS drama The Hunting, starring Asher Keddie and Richard Roxburgh.
[26] On 21 November 2023, Sean Slatter of IF Magazine reported that Joab had been appointed to the board of the National Film and Sound Archive.