Which African country is the most developed in terms of economic relations?

The Republic of South Africa is most suitable. In terms of GDP per capita, it is not in the first place in Africa, it is inferior to Equatorial Guinea and Gabon due to the oil specialization of the latter (small population, a lot of oil), however, its economy is more diverse. It is the leader both on the continent and in the world in the extraction of a number of resources (gold). There is not only a developed mining industry, but also mechanical engineering (the first place in Africa for the production of cars) and agriculture (they grow corn, cotton, sugar cane, cereals).