In many of the challenges faced by the modern world, from overcrowded transportation systems to overstretched healthcare systems, large benefits for society come about from small changes by very many individuals. We survey the problems and the cost they impose on society, and describe a framework for designing "nudge engines"---algorithms, incentives and technology for influencing human behavior. We present a model for analyzing their effectiveness and results from transportation pilots conducted in Bangalore, at Stanford and in Singapore, and a wellness program for the employees of Accenture-USA.

Datacenters are fascinating places, where the massive scale required to deliver on-line services like web search and cloud hosting turns minor issues into major challenges that must be addressed in the design of the physical infrastructure and the software platform. In this talk, I'll briefly overview the kinds of applications that run in mega-datacenters and the workloads they place on the infrastructure. I'll then describe a number of challenges seen in Microsoft's datacenters, with a goal of posing questions more than describing solutions. The audience will leave with a better understanding of how economic factors, technology issues, and software design interact when creating low-latency, low-cost, high availability services.

Interest has been growing in powering datacenters (at least partially) with renewable or "green" sources of energy, such as solar or wind. However, it is challenging to use these sources because, unlike the "brown" (carbon-intensive) energy drawn from the electrical grid, they are not always available. In this talk, I will first discuss the tradeoffs involved in leveraging green energy today and the prospects for the future. I will then discuss the main research challenges and questions involved in managing the use of green energy in datacenters. Next, I will describe some of the software and hardware that researchers are building to explore these challenges and questions. Specifically, I will overview systems that match a datacenter's computational workload to the green energy supply. I will also describe Parasol, the solar-powered micro-datacenter we have recently built at Rutgers University. Finally, I will discuss some potential avenues for future research on this topic.