For more than 20 years he has specialized in the areas of domestic and international tax law and employment and labour law as broadly understood. He has extensive experience in advising on tax optimization for companies, employment issues, incentive plans, employee benefits, services related to employee global mobility, and corporate tax planning. As a director of tax departments and in his own practice, Marcin has provided a full range of tax advisory services, including on personal income tax, transfer pricing, VAT, etc. He represents clients before administrative courts, including the SAC, in various tax and social insurance matters, as well as in fiscal matters and in contacts with tax and government administration.