This meeting will be in-person and is by invitation only to ensure the meeting size is small and vaccination. The meeting aims to bring together leading experts from diverse areas of mathematical statistics and machine learning who are interested in the mathematical foundations of our fields. The common theme of the meeting is modelling and statistical analysis of data from large complex systems, which leads to high-dimensional and structured problems. There will be four special morning lectures: Francis Bach (INRIA), Liza Levina (Michigan), Luc Devroye (McGill), and Judith Rousseau (Oxford). IMS Representative(s) on Program Committees: Caroline Uhler, Piotr Zwiernik