He graduated from the Faculty of Economics and Sociology (specialisation: Foreign Trade) and the Faculty of Management (specialisation: Management Accounting) of the University of Lodz. He holds a certificate of the British Association of Chartered Certified Accountants.
Between 1996 and 1998, he worked as a consultant for PriceWaterhousecoopers. Since 1998, he was associated with the Zurich Group. Initially, he was responsible for the organisation and market strategy of the pension fund and later held the positions of the Marketing Director and Member of the Management Board. From 2000, he was a Member of the Management Board responsible for the Private Client segment of the Zurich Group companies in Poland, and from 2001, he was the Chief Financial Officer. Until the end of June 2006, he was a Member of the Management Board and the CFO of Generali T.U.S.A. and Generali Życie T.U.S.A. From January 2003, he was responsible for the financial department, controlling and bank assurance.
In 2002, he participated in the process of merging Zurich companies with Generali companies. In July 2006, he was appointed as President of the Management Board of BRE Ubezpieczenia Sp. z o.o., and later as President of the Management Board of BRE Ubezpieczenia Towarzystwo Ubezpieczeń S.A.
In August 2007, the Supervisory Board appointed Jarosław Mastalerz a Member of the Management Board of BRE Bank SA for Retail Banking, entrusting him with the coordination of all business and communication activities of mBank in Poland, the Czech Republic and Slovakia, MultiBank, Private Banking and the company Aspiro S.A. established during his term of office.
Since April 2012. Jarosław Mastalerz is a Member of the Management Board of mBank S.A. for Operations and IT and is also responsible for the area of technology and logistics.
He serves on the supervisory boards of ASPIRO S.A., mCentrum Operacji Sp. Z o.o., BRE Ubezpieczenia TUiR S.A., BRE Agent Ubezpieczeniowy Sp. Z o.o., BRE Ubezpieczenia Sp. z o.o., Generali Powszechne Towarzystwo Emerytalne S.A.
