First became known as Argentine Minister of Economy and Production under Cristina Fernández de Kirchner's administration. He would later be appointed the Argentine Ambassador to the United States in 2015.
He earned a Licentiate in Economics from the Universidad de San Andrés before completing a Master's in the subject from the London School of Economics.
He has authored a number of books on economics including 2005's Sin Atajos and 2003's Hacia un federalismo solidario.
His mother's name is Mabel Gellón. He and actress Carla Peterson have a son named Gaspar.
He was appointed Argentine ambassador to the United States in 2016 by President Mauricio Macri.