Peter Sewell is a Professor of Computer Science and EPSRC Leadership Fellow at the University of Cambridge Computer Laboratory. His research aims at establishing mathematically rigorous foundations for the engineering of real-world computer systems, to make them better-understood, more robust, and more secure. He and his colleagues have recently focussed on the relaxed-memory concurrency models of multiprocessors and concurrent languages (x86, ARM, IBM Power, and C/C++11), on verified compilation of concurrency (CompCertTSO and the concurrency compilation schemes from C/C++11 to x86, Power, and ARM), and on tools for applied semantics. He has also worked on programming languages, network protocols, security, and concurrency theory.