Miroljub Kostić obtained his PhD from the Faculty of Organizational Sciences with a thesis on data protection in the official statistics system. After graduating from the Faculty of Mathematics where he studied numerical mathematics and cybernetics, he enrolled at the computer science postgraduate program, where he earned the aforementioned PhD. He worked at the Statistical Office of the Republic of Serbia, first as a programmer, and then as a senior information system designer. He subsequently became the head of the Design and Programming Department, and finally the head of the Information System Design and Programming Department.

He was assistant director at the Information and Communications Technologies Department (2002-2011). Throughout his long-standing career, he simultaneously worked as a teaching assistant in Mathematics and Computer Science at the Faculty of Agriculture, as well as in Applied Statistics and Computer Science at the Faculty of Geography.