Dennis received a BSc (Hons) degree in Electrical Engineering in 1987 from the University of Southampton, England. He has since worked in various industries including mining, auditing, petrochemicals, electricity utility, management consultancy, financial services, and telecommunications. Dennis is responsible for the expansion of Mint Management Technologies (Pty) Ltd into the rest of Africa (outside South Africa). He also serves as an independent director on the Board of Cognition Holdings Ltd.