Cullen currently serves as Director of the Platform Architecture Lab where he leads a multi-disciplinary team of researchers investigating computer architecture ranging from data centers to distributed systems. His team focuses on a wide range of inter-related topics including system and fabric architecture, thermal science, mechanical design, management systems, Internet of Things, and software-hardware co-design.
Prior to his current role he was interim director of the Sustainable Ecosystems Research Group at HP Labs where he led wide-ranging research into the sustainability of IT equipment, and the use of IT to improve the sustainability of customer ecosystems. During this time, he was also Principal Investigator of the Sustainable Data Center project which investigated the design and operation of data centers to reduce overall resource consumption. In previous roles, he has led research in thermal technologies over a variety of different length scales, from integrated circuits to data centers.
Cullen is a Fellow of the American Society of Mechanical Engineers and a Senior Member of IEEE.