After graduating from Georgetown University’s School of Foreign Service in 1990 with the BSFS/MSFS degrees, Semsar founded the Development Institute International (DII), one of France’s leading conference providers, in 1993. In 2015, she became the founding Chief Executive Officer of POLITICO Europe, a position she held until 2021. Under her leadership, it became one of the most influential non-partisan publications ever launched in the continent, dominating the Brussels media scene. Prior to POLITICO, Semsar was the owner and publisher of European Voice, the leading media outlet in Brussels covering E.U. policy, which she acquired from the Economist Group in 2013.
Semsar has maintained strong ties to her alma mater. In 2021, she joined the McCourt Institute, an academic partnership between Sciences Po and Georgetown University’s McCourt School of Public Policy, as its inaugural Executive Director. She is also currently serving on the Advisory Board of the School of Foreign Service and the Georgetown Institute for Women, Peace and Security, and was a member of Georgetown University’s Board of Directors from 2013 to 2019. She has also supported the Semsar-de Boisséson Scholarship, a fellowship awarded to one MSFS student per year.