He gained his professional experience in the Government Legislation Centre, the Prime Minister’s Office, the Office of the Council of Ministers and the Ministry of Finance. He managed the Stopczyk & Mikulski Sp.k. Law Firm for 15 years.

Since 2006, he has been involved in the key railway modernisation projects in Poland co-financed by the EU assistance of the value over EUR 5 billion.

He is the author of the constitutional complaint under which the Constitutional Tribunal in its judgment of 15 April 2014 in the SK 12/13 case, decided that Article 34 section 2 of the Act on court fees in civil proceedings is unconstitutional. This enabled many injured parties to defend their rights.

He actively participates in energy development projects and he is a member of the management board of the Polish Hydrogen Association.

He is the co-author of many legal acts in the field of public procurement law, public finance law, commercial insurance law, intellectual property protection law and environmental protection law as well as the valued author of numerous publications in newspapers and on professional websites.

He coordinates and supervises legal counselling for the Clients of the Law Firm. He is the legal representative in litigation of many domestic and foreign investors in key disputes before civil and administrative courts and the Public Procurement Office.