Sebastián is a sixth-year doctoral candidate in the Department of Sociology. His research spans political sociology, organizational sociology, and the sociology of development. His dissertation explores the extent to which state agencies in Colombia, amidst ongoing conflict and multiple peace negotiations since the 1980s, became pockets of organizational effectiveness while implementing peace-related policies. Sebastián's broader research includes the history of violence as a topic of social scientific study in Latin America, the comparative historical sociology of the state, and the response of U.S.-based nonprofits to changes in domestic legislation.

Sebastián graduated summa cum laude from New York University Abu Dhabi (NYUAD) in 2017, where he studied Social Research and Public Policy with a concentration in Economics. At Princeton, he was Lassen Fellow in the Program in Latin American Studies during the 2019-2020 Academic Year.