Vesa Apaja is a seasoned theoretical physicist, especially interested in quantum many body physics and computational physics. His first research topic was quantum fluids as a research assistant in the Department of Physics at the University of Oulu from 1990 to 1999. During that time he realised the importance of the computational approach to many body physics and wrote his first Quantum Monte Carlo codes. In 1999, he ventured to Austria, where he joined the Many-Body Theory group at the Institut für Theoretische Physik, Johannes Kepler Universität, Linz. As a Universitäts Assistent, he expanded his research horizons to excitations in quantum fluids, and intricacies of diagrammatic many-body theory and statistical physics. In 2006, he joined the Department of Physics at the Nanoscience Center, University of Jyväskylä, Finland, where he continues to serve as a senior researcher to this day. His contributions in this role have been in a wide variety of condensed matter topics, such as flat band lattice dynamics and electrochemistry on surfaces using Kinetic Monte Carlo. In recent years, teaching Statistical Physics, Efficient Numerical Programming, Numerical Applications in Physics, and Quantum Monte Carlo has taken most of his time. He also possesses proficient programming skills in Python, Julia, Fortran, and C++, which have been instrumental in designing and implementing advanced simulations and computational models to analyse complex physical systems.