An acclaimed American playwright, screenwriter, and director, he gained recognition in the late 1990s with his play "This Is Our Youth." Transitioning to film, he co-wrote "Analyze This" and "Gangs of New York." His directorial debut, "You Can Count on Me" (2000), was lauded for its nuanced storytelling. He achieved further success with "Margaret" (2011) and "Manchester by the Sea" (2016), winning an Academy Award for Best Original Screenplay. His works often explore complex human emotions and relationships.