Preparations for exascale computing have led to the realization that computing environments will be significantly different from those that provide petascale capabilities. This change is driven by energy constraints, which has compelled hardware architects to design systems that will require a significant re-thinking of how application algorithms are selected and implemented. The “codesign” principle may offer a common basis for application and system developers as well as architects to work synergistically towards achieving exascale computing. This paper aims to introduce to the embedded system design community the unique challenges and opportunities as well as exciting developments in exascale HPC system codesign. Given the success of adopting codesign practices in the embedded system design area, this effort should be mutually beneficial to both communities.