Transition metal oxides are of fundamental interest because of their emerging properties — exotic magnetism and superconductivity, divergent susceptibilities, metal-insulator transitions, etc. — which are caused by the strong correlations between the electrons. Recent developments in experimental thin-film growth techniques offer the possibility to create oxide heterostructures, allowing materials with different chemistries to be combined to optimize existing behaviors and engineer entirely new functionalities. The primary objective of project D&D5 — Correlated Transition Metal Oxides and Heterostructures — is to design heterostructures with novel functionalities that can enable disruptive technologies for electronics and energy applications. Along the way, we will extend the methodologies developed in MARVEL phase I to the description of point defects, which we have shown are key to a complete description of oxide heterostructure physics and function.