Sen is a senior research fellow at the Institute of South Asian Studies and Asia Research Institute, National University of Singapore. He is the author of Articles of Faith: Religion, Secularism, and the Indian Supreme Court, and has co-edited several books, including Being Muslim in South Asia: Diversity and Daily Life. He has a Ph.D. in political science from the University of Chicago, and read history in Presidency College, Calcutta. He has been an editor with the Times of India.