Our research focuses on designing experimental software systems with an emphasis on improving their sustainability and energy-efficiency. We solve problems arising from the rapid growth in the energy usage and cost of modern computing platforms, which span cloud data centers, distributed sensors, and mobile devices. We also design systems that leverage computation, networking, and sensing to improve society’s sustainability, such as optimizing the energy usage and cost of smart electric grids and buildings. As such, our research cuts across multiple areas, including operating systems and virtualization, distributed systems and networking, cloud computing, embedded sensor systems, security and privacy, data analytics, and economics. Our research approach is experimental in nature and focuses on designing, deploying, and analyzing functioning prototypes at scale.