He has served as the Vice-President of the Management Board of the Foundation, providing expert advice on oil, mining, gas and the energy sector. In recent years, he has also sat on the supervisory boards of a number of Polish companies. Before that, Mr. Z. Leszczyński served as the President of the Management Board of Wodociągi i Kanalizacja w Opolu Sp. z o.o., President of the Management Board of Rynex Sp. z o.o., President of the Management Board of Wisła Płock S.A., Head of Sales and Marketing at Kompania Węglowa S.A. He has also provided advisory, supervisory and project management services as a sole trader.