Editor of The New Yorker magazine since 2017, he has collaborated on it since 2011, writing about technology, social media, far-right and press, as well as comedy and pop culture. He divides his time between writing articles addressing topics such as hip-hop purism and Truman syndrome, and editing other stories about Las Vegas nightclubs or Lebanese warlords. Marantz's main interest lies not in any particular topic, but in how people form beliefs and under what circumstances those beliefs can change for the better. Marantz is also a contributor to Radiolab and The New Yorker Radio Hour, and has written for Harper's, Mother Jones, The New York Times and many other outlets. Since 2016, he has been working on his book Antisocial on the dangers of virality, the myth of linear progress, and the American far right. To document himself, he spent several years infiltrating some groups of conspirators, white supremacists and internet trolls. In the process, he saw how some of the earliest and most influential founders of social media are now beginning to be aware of the force they had unleashed. Marantz holds a bachelor's degree in religion from Brown University and a master's degree in literary nonfiction from New York University.