David is the Big Data Architect and Chief Technologist of the Stanford Internet Observatory. Prior to Stanford, David worked at Facebook, primarily focusing on security and safety for Facebook Connectivity, a collection of projects aimed at providing faster and less expensive internet connectivity to unconnected or underconnected communities. Projects included the Terragraph mesh networking system, the Magma open source mobile network platform, Express Wi-Fi and Facebook Lite.

Before Facebook, David was a VP at iSEC Partners and later NCC Group, managing the North American security consulting and research team, as well as producing original security research, coordinating vulnerability disclosure and performing security assessments and penetration testing for companies across a wide range of business sectors.

David has spoken at various industry conferences, including Black Hat, DEFCON, PacSec and SOURCE Boston. He is also the author of iOS Application Security (No Starch Press) and coauthor of Mobile Application Security (McGraw-Hill).