Paweł Lorek obtained his PhD at the University of Wrocław in 2007, where he is currently a professor at the Faculty of Mathematics and Computer Science. His main scientific interests include Markov chains (in particular, the rate of convergence to stationarity and duality-based methods), computer security, and probabilistic aspects of machine learning. Tomasz Rolski obtained his PhD at the University of Wrocław in 1972, where he is currently a professor at the Faculty of Mathematics and Computer Science. He is the author or co-author of about 90 scientific publications and three books in various areas of applied probability. His main mathematical interests include queueing theory, point processes, ruin theory, and life insurance mathematics.