Daniel N. Wilke, is an Associate Professor at C-AIM, Mechanical and Aeronautical Engineering, University of Pretoria, with a research focus on generative modelling that includes physics-based (finite and discrete element modelling) and data-driven modelling (optimization formulation driven) to enable digital twin technology. He is also known as the(/that) Gradient-Only Optimization Guy and co-authored Practical Mathematical Optimization in the Springer Optimization and Its Applications Series, 2018 with the late Prof Jan Snyman. Optimization is his passion, generative modelling his application and Nvidia GPUs his calculator.