Microstructure heterogenization is broadly employed to enhance the strength and ductility of materials. Typical routines include realizing bi-modal grain size distribution in polycrystalline metals, making multi-phase alloys such as dual-phase steels, adding dispersed crystalline phase in monolithic metallic glasses, and so on. Recently, the combination of heterogeneous microstructures with gradient shows a synergetic effect in realizing better strength and ductility. In this talk, we will discuss how heterogeneous microstructures could be realized in engineering level structures. We take the twin-induced plasticity steel and high entropy alloys as model cases, and show the enhanced mechanical properties due to the presence of heterogeneous structures at micro to nanoscale. We also discuss the physical origin which leads to the superb hardenability and deformability in those materials.