- European constitutional law
- European economic law
- Differentiated integration (EU-Switzerland, EEA, EU-UK)
- International and European human rights law
- International and European asylum and migration law
- International and European environmental and sustainability law
- Relationship between national law and international law/European law
- Comparative constitutional and international law
- Fundamentals of law, philosophy of law, legal theory
- American Society of International Law
- Arbitration Panels under Article 171 of the EU-UK Withdrawal Agreement, Reserve Member
- Association of German Constitutional Law Professors (VDStRL – Vereinigung der Deutschen Staatsrechtlehrer)
- Austrian Commission of Jurists
- Austrian Review of International and European Law (ARIEL), Member of the Editorial Board
- Austrian Society for European Law
- Austrian Society of International Law
- Enhancing Climate Action through International Law (EnAct), University of Copenhagen, Member of the Scientific Advisory Board
- European Communities Studies Association (ECSA) Switzerland, Member of the Board of Directors
- European Law Advisory Board of the Federal Ministry for European and International Affairs, Vienna
- European Society of International Law (ESIL)
- German Society for International Law (DGIR – Deutsche Gesellschaft für Internationales Recht)
- German Society of Constitutional Law - Vereinigung der Deutschen Staatsrechtslehrer
- International Commission of Jurists - Swiss Section
- International Law Association (ILA), Austrian Branch
- International Law Association (ILA), Committee on International Migration and International Law
- International Society of Public Law (ICON-S), Austrian Chapter, Member of the Advisory Council
- Vienna Journal on International Constitutional Law (ICL), Member of the Advisory Board
