Rumiana lectures International Law, EU External Relations, International Human Rights Law and International Criminal Law. She supervises International and European Union Law. Her research interests lie in the areas of general international law, particularly its sources and the responsibility of States, the settlement of international disputes, international investment law, and the nascent field of international biomedical law. Rumiana's publications center around international communitarian norms and their legal effects in different regimes. She practices as an Academic Door Tenant at Thomas More Chambers where she advises on investment arbitrations. Rumiana completed her PhD in Cambridge under the supervision of Prof. James Crawford and assisted him with cases as his Research Associate. Prior to this, she spent time at the Secretariat of the Permanent Court of Arbitration, the European Commission in Brussels and the International Tribunal for the Law of the Sea. Rumiana did her Magister Juris at the University of Sofia, an LL.M Advanced in International Law at Leiden University and was awarded the Hague Academy Diploma in International Law cum laude. She was a founder and editor-in-chief of the Cambridge Journal of International and Comparative Law (now Cambridge International Law Journal). Rumiana is a fellow at the Lauterpacht Centre for International Law, a member of the Centre for European Legal Studies, the Cambridge Centre for Law, Medicine and Life Sciences, and a Visiting Professor at McGill.