Mr Diphofa became the Director-General of the Department of Traditional Affairs with effect from 01 February 2018. He was the Director-General of the Office of the Public Service Commission (OPSC) between 2010 and 2011, and the Director-General of the Department of Public Service and Administration (DPSA) from November 2011 to January 2018.

During his tenure at the OPSC, he also served as the Secretary of the African Association of Public Service Commissions, a professional body for Public and Civil Service Commissions in the African Continent. As part of his responsibilities as Director General at the DPSA, he also served as chairperson of the Governance and Administration Cluster of the Forum of South African Directors General (FOSAD)

He has previously also served as Deputy Director-General, Monitoring & Evaluation and later Deputy Director-General, Leadership and Management Practices at the OPSC and as Chief Director (Service Delivery Improvement Branch) at the DPSA.

Mr Diphofa has also held various positions within the Joint Education Trust, an agency established in 1992 as a partnership between business, labour, community and political organisations to provide support to development initiatives in the field of Education and Training. His last position in the Joint Education Trust was that of Deputy Executive Director.

Mr Diphofa has also worked as a teacher-educator at Colleges of Education, and as a Researcher for the Community Agency for Social Enquiry (CASE). He has also served in the boards of the Gauteng Youth College, the Government Employees Pension Fund (GEPF) and the Government Employees Medical Scheme (GEMS), and as Vice President (Southern Africa) of the African Association of Public Administration and Management (AAPAM)

Mr Diphofa holds BAPaed, and BEd degrees from the University of the North (Turfloop) and Master of Education and Master of Management (Public and Development Management) degrees from the University of the Witwatersrand.