Senior Research Fellow at the Institute of Comparative Law, Belgrade, Serbia. She holds a doctoral degree in Criminal Law. She has experience as a consultant for the projects funded by the European Union, as well as a consultant for the World Bank, GIZ, Centre for Integrity in the Defence Sector (CIDS). Jelena Kostić was also engaged as a lecturer on Judicial Academy.

She is the co-author of several handbooks of importance for the field of justice:

• System of financial management and control in public prosecutor's offices;
• Confiscation of property resulting from a criminal offense: challenges and recommendations for improving the procedure;
• Practicum for investigations and trials of criminal acts of corruption and
• Analysis of Position of Judicial Assitants in the Republic of Serbia with recommendations for improvements.

Jelena Kostić published a number of papers and a few monographs in English and Serbian. Jointly with dr Marina Matić Bošković in 2024 she wrote “Track Record in fight Against Corruption in Serbia – How to Increase Effectiveness of Prosecution”, Journal of the University of Latvia. Law, No. 17/2024, in 2023 she wrote „Criminal law as an effective tool to protect environment?“ In: Collection of papers from the International Scientific Conference „Bratislava Legal Forum” Comenius University, Faculty of Law, 74-91, 2, in 2022 she wrote “Financial Accountability and Transparency of Public Sector Institutions in the Republic of Serbia”, in Mikuli, P., Kuca, G. (eds) Accountability and the Law, Routledge.

She was engaged as a lecturer at the Faculty of Law of the “Megatrend University” in Belgrade, and was an invited lecturer at the Law Department of the University of Salerno, the Faculty of Law of the University of Niš and the University of “Niccolo Cusano” from Rome.