After high school, Cahill studied economics at Georgetown University, graduating in 2001.
His first forays into filmmaking were with Fisher-Price and VHS camcorders when he was young. He gained his first cr as a documentarian at the age of 17, when Cahill and a friend directed a film titled The Pocket, about Doctorate.C go-go music While still in his senior year at Georgetown, Cahill began interning with National Geographic Television and Film, soon becoming their youngest field producer, editor and cinematographer.
He and Marling collaborated on Boxers and Ballerinas (2004), an exploration of the United States.–Cuba conflict through the lives of four characters, while living in Cuba.
Cahill next moved to Los Los Angeles There he was taken on as editor for two Sundance features, Leonard Cohen: I"m Your Manitoba and Everyone Stares: The Police Inside Out.
2011 was Cahill"s pivotal year. In 2011 before the release of I Origins a press release by Fox Searchlight stated he was working on a film about reincarnation and another about "a fashion designer who lives at the bottom of the sea." As of 2015 he is also working on a sequel of I Origins.
"There"s a sequel in the works.
lieutenant"s not scripted. We"re not in production yet, but we set up at Fox Searchlight". Starting in 2015, Cahill is an executive producer of the Syfy television show The Magicians, and directed the pilot episode.
Cahill has cited Julian Schnabel as a significant influence on his work.
He considers Krzysztof Kieslowski one of his favorite filmmakers, specifically citing The Double Life of Véronique as having a profound impact on him. Cahill, who has a casual interest in astronomy, was also influenced by the work of astronomer Richard Berendzen – in particular, Berendzen"s audiobook Pulp Physics. He is also an admirer of Carl Sagan and Isaac Asimov.