Juba's career started at Eskom where he was appointed Group Human Resources Manager for the Services Group in 1995. In 1997 he was appointed Human Resources Director of Simba (Pty) Limited, and his role was expanded in 2004 to include human resources responsibility for the PepsiCo businesses in Sub-Sahara Africa. In October 2004 Juba was appointed to the Board of Mittal Steel South Africa as Executive Director, Human Resources. In this role, Juba also served on the Human Resources and Nominations Committee, the Transformation Committee, as well as the Safety, Health and Environment Committee of the Mittal Steel Board.

Juba has been appointed Human Resources Director of Aveng with effect from 1 October 2007