Ronald Bronstein is an American film director, screenwriter, editor and actor. He directed, wrote and edited the 2007 film Frownland. He is also known as a prominent collaborator of the Safdie brothers, having acted as editor on all their features and co-written all their screenplays since 2009's Daddy Longlegs. Description above from the Wikipedia article Ronald Bronstein, licensed under CC-BY-SA, full list of contributors on Wikipedia.