Modern compilers are complex pieces of software implementing a large number of optimizations that interact in many complex ways. Moreover, these optimizations often have conflicting effects on performance, power, energy, memory consumption, etc. This research project aims at studying how to fine-tune and explore the compiler design space so that a compiler optimizes multiple criteria – in contrast to prior work which typically uses heuristics and/or single-criterion exploration. We will consider both static and dynamic compilers (virtual machines) as part of this research project.