Jagna is an Associate Professor at the Chair of Transnational Law, Faculty of Law and Administration at the University of Warsaw, where she also serves as the Dean’s Proxy for International Programmes. She has been a Visiting Scholar at Harvard Law School, Ludwig Maximilian University in Munich, and the Centre for Socio-Legal Studies, University of Oxford.

Her academic work focuses on Polish, international, comparative, and European consumer law, as well as various forms of dispute resolution. She conducted empirical research projects on consumer collective redress (class actions) and consumer law enforcement, funded by the Polish National Science Centre. Her broader research interests include access to justice and alternative dispute resolution (ADR), particularly in the consumer law context.

She is the author of the book Consumer Collective Redress in EU Law: Lessons from the Polish Legal System (Routledge, 2025).