Markus Burgstaller combines experience in public international law and EU law at the highest level of government with many years of experience in private practice. He acts for States, international organisations, businesses, and individuals in international disputes, mainly arbitrations under ICSID and UNCITRAL rules, and in proceedings before the Court of Justice of the European Union (CJEU). He is nominated to the ICSID Panel of Arbitrators by the Austrian Government.

Markus was lead counsel for the Slovak Republic in the Achmea case before the CJEU in which the CJEU ruled that EU law precludes a provision in an international agreement concluded between EU Member States that provides for investor-State arbitration. For his work Markus received the Financial Times Innovative Lawyers award for innovation in legal expertise – dispute resolution, the award for "Most Important Decision" by Global Arbitration Review and was named "Lawyer of the Week" by The Times.

Recognized as a leading individual in public international law in the UK and globally, Markus guest lectures at universities such as the University of Cambridge, the London School of Economics and Political Science, and Humboldt University in Berlin.  Markus is frequently interviewed and published in international media such as the Financial Times, The Economist, The Times, the BBC, and the Frankfurter Allgemeine Zeitung.