In this workshop we will consider applications of lattice field theory techniques to simulate the dynamics of interacting fields in the early Universe. We will introduce CosmoLattice, a public code recently developed for lattice simulations of early Universe scenarios. We will consider application of CosmoLattice as a tool to simulate the non-linear dynamics of field theories in the early Universe, considering modern applications to preheating scenarios, baryogenesis, gravitational wave production, non-minimally coupled scalar fields, axion-like fields, cosmic strings, and others if time permits.