David Dill is Lead Researcher, Blockchain at Facebook. My research has focused on formal verification, computational biology, and voting technology and policy. My main focus now is formal verification. In formal verification, I worked on many different approaches and applications and made many contributions to that area in automata theory (timed automata), BDD-based model checking, explicit state model checking, CPU verification methods, and decision procedures for quantifier-free logic (SMT solvers). My google scholar profile shows publications in this area. Dill has interests in the theory and application of formal verification techniques to system designs, which encompass hardware, protocols, and software and in computational systems biology. He has also done research in asynchronous circuit verification and synthesis, and in verification methods for hard real-time systems. He retired in 2017 and is no longer taking new students. He is currently a researcher at Facebook on blockchain technology.