She holds a law degree from the University of Warsaw and a postgraduate degree from the School of Economics. She also studied at Oxford University and the International School of Private Law in The Hague. She gained professional experience in international law firms. She then worked at Hewlett Packard (2007-2018) and Skanska (2018-2022) as Head of Legal and Compliance for Poland and Central Europe. Between 2012 and 2018, she was involved in the work of the Polish Chamber of Information Technology and Telecommunications, among others as vice-chair of the Intellectual Property and Digital Market Committee. From 2009 to 2014, she was vice-chair of the Consumer Products Committee of the American Chamber of Commerce. She is currently a member of the Council of the Finnish Trade Guild within the Polish-Scandinavian Chamber of Commerce. Since 2022, she has been working for Nordea Bank, currently as Director of the Nordea branch in Poland, while supervising the legal department of the organisation.

Agnieszka Dzięgielewska-Jończyk is also vice-president of the Polish Association of Corporate Lawyers, a member of the Women in Law Foundation Council and a mentor. In 2021, she was included in Forbes’ list of 25 women lawyers in business.