The modeling of the effects related to the existing interactions between defects and interfaces of ultra-thin heterophase layers composed of two metals with positive enthalpy of mixing is the key to improve the understanding of the fundamental mechanisms that modify the physics of these systems in the region surrounding the interface. The objective of the project is to capitalize this knowledge to eventually develop systems with well defined interface characteristics, exceeding the performance of current materials (thermal barriers, coatings, ...). We team up theoretical models, numerical and experimental approaches to solve this problem, to accelerate the discovery of the most promising metal couples, to predict their behavior in deployment conditions (these conditions are intrinsically out-of-equilibrium), and to develop and validate predictive models that ultimately help us designing advanced materials that exploit the metastability of particular architectures and microstructures.