Tomasz A. Wesolowski was born in Trzcianka (Poland). He earned his Ph.D. (with Professor David Shugar) in 1991 awarded by the Faculty of Physics at the University of Warsaw for his work on modeling cooperative binding of calcium ions in proteins. In 1991, he joined the group of Professor Arieh Warshel (University of Southern California, Los Angeles) where he started working on multilevel simulation methods and density functionals for coupling the quantum-mechanical descriptors with the environment in particular. In 1994, he moved to the University of Geneva, working initially as a postdoctoral researcher, then Lecturer and Research Group Leader, and since 2012, as associate professor in the Physical Chemistry Department. His research concerns mainly the theory of embedding a quantum system and its applications in multilevel simulations of embedded chemical species. His other research interests include density functional theory formulation of quantum many-electron problem, orbital-free density functional theory methods, and all sorts of molecular simulations.