Poloko trained at the University of Oxford as a scientist focusing on the molecular genetics of cancer. He qualified for his doctorate degree in 2003 and continued his post-doctoral fellowship at the National Institutes of Health (NIH) in Baltimore Maryland. As a scientist, Poloko conducted a fellowship at the NIH in Bethesda, Maryland, and the Medical Research Council in Harwell, United Kingdom. Upon returning to South Africa, Poloko changed career and joined Letsema Consulting in 2007 as a management consultant. His focus was primarily on strategy consulting and in 2009 Poloko set up his own consulting practice, which underwent a few partnerships and currently exists as a company called William Radcliffe. William Radcliffe focuses on governance and company secretariat consulting. Poloko subsequently served as the COO of Batswadi Consumer Healthcare, which is a South African company focused on sales and distribution of medical and laboratory equipment and supplies.
Poloko joined the board of Deltamune in February 2015 and serves on the finance and risk committee. Since retiring from his role as COO of Batswadi Consumer Healthcare, Poloko has returned to serve as the CEO of his consulting practice, William Radcliffe.