David Hummel is since October 2016 legal secretary (référendaire) at the European Court of Justice at the cabinet of Advocate General, Juliane Kokott. Before (2013 – 2016) he represented several tax law chairs at the Universities of Münster, Trier, Leipzig and Hamburg. In mid-2017 he was appointed as a Professor at the University of Leipzig. His academic career starts with the Study of Law at the University of Leipzig, a Graduation (Phd) as an assistant of Prof. Dr. Stadie with a VAT-Thesis in 2009 and a Habilitation in 2013 with the matter: “Rechtsformneutralität im Öffentlichen Recht“ (neutrality of legal forms in public law – venia legendi: public law, especially tax law and public economic law).