- Focus of practice: Public procurement law
- Study and traineeship in Münster, Cologne, Barcelona, Mönchengladbach and Bologna
- Practice as lawyer at a renowned law firm in Cologne
- Founder of the firm Hattig und Dr. Leupolt Rechtsanwälte at Ebertplatz in Cologne
- Numerous publications in the area of public procurement law and public economic law
- Consultancy for the European Union in the area of public procurement law e.g. in Macedonia and Romania