John Mitchell worked for Gold Fields Mining and Development for 12 years. During this period he designed and instituted a job evaluation system, personally presenting skills training courses to the management and staff of the mines. As Group Personnel Officer, he developed his natural rapport with people as well as his presentation skills. He is a Competent Toastmaster.

Later in his career he managed Gold Fields Printing (Pty) Ltd. where he obtained a practical knowledge of business finance, introducing modern accounting methods to control the operation. He gained additional experience in negotiation and the evaluation of companies in the Capital Procurement Department of Gold Fields, and left the company at the end of 1997 when it changed ownership.

Since 1998 he has been presenting training courses in business finance for Johannesburg School of Finance. He served as a Director for the company from 2004 to 2020 when he resigned for administrative reasons.

Was a member of the Investment Analysts Society, a forum for the presentation of company results to analysts, from 1997 to 2024.

He holds a BA Degree in Philosophy from the University of Cape Town.