Under the post-apartheid presidential administration of Thabo Mbeki, Langa served as Chief Justice in the Constitutional Court of South Africa. Previously, he had served as Deputy President and, later, Deputy Chief Justice.
After working in the language and communications division of the South African Department of Justice, he earned his law degree from the University of South Africa.
As a member of both the African National Congress' Constitutional Committee and the National Association of Democratic Lawyers, he helped write the South African Bill of Rights.
His brother, Bheki Winston Joshua Langa, was a South African diplomat to both Russia and China.
Nelson Mandela appointed Langa to South Africa's Constitutional Court in the mid-1990s.