His first published work was in New Mutants Annual #6 (Marvel Comics, 1990). Most notable work is MELTDOWN (Image Comics), which received significant accolades and was named to several annual Top 10 lists for 2006 and 2007. Most recent work is "Aspen Showcase: Ember", from Aspen Comics. At the 2009 San Diego Comic-Con, Schwartz was announced as the writer of a new arc of Aspen Comics' series "Fathom".
David also dabbled in screenwriting. Credits included the feature film "Fighting Gravity" (CC Films, 1997, winner of various film festival awards), and the syndicated sketch comedy TV series "The Newz".In addition to writing, David is an executive at The Walt Disney Company.