Materials deformation is ultimate controlled by physical processes at the atomic scale. In many cases, these processes are controlled by fluctuations characterized by highly stochastic behavior. While we have learned to subsume this stochasticity into continuum laws that describe average behavior, as science and technology pushes down the boundaries of what is observable in terms of time and length scales, the mean field approach becomes to be questionable. Specifically, important phenomena in metals deformation such as creep, dynamic strain aging, solute hardening, and deformation processes in chemically complex alloys cannot be properly studied without capturing atomic-level fluctuations and their effect on meso/macroscopic behavior. In this presentation, I will discuss the development of models that take into account thermal and compositional fluctuations explicitly and how their results can be extended into larger length and longer time scales. Results for refractory transition metals, ferritic materials, and high-entropy alloys will be shown.