[2] Later in his career, while a practising attorney, he pursued postgraduate education at the University of Johannesburg, graduating with an LLM in 1992 and a diploma in advanced corporate law in 1996.
[1] He ran that firm for the next six years, during which time he was the chairperson of the North West branch of the Black Lawyers Association from 1992 to 1996 and the president of the Law Society of Bophuthatswana from 1996 to 1998.
[8] In mid-2009, Bosielo was one of four candidates who was shortlisted for possible elevation to the Supreme Court of Appeal;[9][10] he was interviewed by the Judicial Service Commission in July that year in Cape Town.
He also wrote a minority judgement in State Information Technology Agency v Gijima Holdings which was upheld unanimously by the Constitutional Court.
[2] During his first acting stint, he wrote the Constitutional Court's unanimous judgement in the Labour Appeal Court matter of Grootboom v National Prosecuting Authority; in 2016, he wrote unanimous judgements in Raduvha v Minister of Safety and Security, on the rights of detained minors,[1] and McBride v Minister of Police, on the independence of the Independent Police Investigative Directorate.
He was first interviewed for the apex court in June 2012, as one of four candidates, alongside Raymond Zondo, Mandisa Maya, and Robert Nugent, for the vacancy created by Sandile Ngcobo's resignation.
[14][4] On that occasion, though he was viewed as a "dark horse" candidate, Bosielo performed strongly, stressing his commitment to access to justice and fielding questions about judicial restraint and the separation of powers.
[17] Bosielo was next shortlisted and interviewed in February 2013, one of five candidates for Zak Yacoob's seat on the Constitutional Court,[18] and he was again recommended for appointment on that occasion, alongside Brian Spilg, Selby Baqwa, and Mbuyiseli Madlanga.