In December 2016, Judge Trendafilova was appointed the first President of the Kosovo Specialist Chambers based in The Hague, The Netherlands. As a Judge at the International Criminal Court (2006-2015), Judge Trendafilova was Presiding Judge in the Pre-Trial Division in the cases stemming from the situations in the Republic of Uganda, the Central African Republic, Republic of Kenya, the Democratic Republic of the Congo, Sudan (Darfur), Cote d’Ivoire, Mali. She has also served as President of the Pre-Trial Division. Judge Trendafilova sat as a Judge of the Appeals Chamber on the first final appeals in the cases of the Prosecutor v. Thomas Lubanga Dilyo and the Prosecutor v. Mathieu Ngudjolo Chui.
Judge Trendafilova has extensive experience in criminal law, criminal procedural law, evidence law, international and comparative criminal law, criminal justice and human rights. She has been a Professor of Criminal Justice and International Criminal Justice at Sofia University since completing her PhD in 1984 as well as a deputy district attorney at Sofia District Court (1985-1989) and a barrister (1995-2005). She was the representative of Bulgaria to the UN Commission for Crime and Criminal Justice (1992-1994). Judge Trendafilova chaired the working group on the reform of the Bulgarian criminal procedure in line with European and international standards for efficient administration of justice and protection of human rights (1998-2000). She chaired the Criminal Division of the Legislative Consultative Council with the President of the Parliament of Bulgaria (2001-2006). Judge Trendafilova has been granted Alexander von Humboldt (1993-1994) and Fulbright (1997) scholarships. She has publications in the field of international criminal justice, comparative criminal law and procedure and human rights. Judge Trendafilova has been awarded by the Government of Bulgaria and non-governmental organizations for her contribution to the legal reform, the administration of justice and the rule of law.