Janusz Cieszyński worked as advisor of Prime Minister Mateusz Morawiecki while the latter was in charge of the Ministry of Development and Finance. In 2016-2017 he was director of the Department of Small and Medium-Sized Enterprises in the Ministry of Development.

He also ran a company that advised SMEs in business and legal affairs. From 2009 to 2014 he worked in one of the largest telecommunication companies. He graduated in Finance and Accounting at the Warsaw School of Economics.