Gustavo broke into law with an AmeriCorps-Justice Corps role with the Legal Aid Society of San Diego. He later worked as a legal assistant for a Los Angeles-based firm specializing in employment law, where he assisted attorneys in drafting discovery responses and preparing clients for deposition. While in law school, Gustavo worked as a legal intern for the largest law firm in Argentina, and as a law clerk for The City of Carmel Office of Corporation Counsel. In addition, Gustavo served as a judicial extern for Justice Christopher M. Goff of the Indiana Supreme Court. Gustavo also volunteered as a certified legal intern for the Protective Order Project, which assists domestic violence survivors.