Kieren has a broad commercial and equity practice at the Bar, in areas ranging from corporations law disputes, to probate and property litigation and general commercial litigation.

He has particular expertise in construction and engineering disputes, having been briefed in major construction arbitrations including those concerning the AirportLink tunnel in Brisbane, the Basslink electricity interconnector, the BassGas gas processing facility and the Studland Bay Wind Farm. He has appeared in a number of disputes concerning security of payment legislation.

Since 2015, Kieren has been listed by Doyle's Guide as pre-eminent or leading junior counsel in Melbourne for construction disputes, and recommended by Best Lawyers in the field of Construction/Infrastructure Law.

Kieren has also been a lecturer in Corporations Law at the University of Melbourne.