David is a private investor, an active philanthropist, and a supporter of many progressive groups and organizations. David and his wife Nancy Blachman are founders of the Julia Robinson Mathematics Festival, a program of math education and enrichment for middle and high school students. A mathematician and software engineer, David was among the first 20 employees at Google, where he worked from 1999 to 2005. Since leaving Google, David continues to engage with mathematical research. David is a trustee of the University of California Berkeley Foundation, and a member of two visiting committees at MIT. David has degrees from MIT and the University of California at Berkeley. His dissertation involved the analysis of a mathematical game, with applications to information theory.