Serrat is a Junior Professional Officer in the Department of Safeguards at the International Atomic Energy Agency. JPOs are sponsored by the U.S. Support Program to IAEA Safeguards, which is funded primarily by the U.S. Department of State. Serrat collects and analyzes open source information on the nuclear programs and resources of various countries and works with teams of inspectors, imagery analysts, and others to reach safeguards conclusions: whether a country has diverted nuclear material or built a clandestine facility. He was previously a research associate at the James Martin Center for Nonproliferation Studies where he worked on the same issues — sanctions, anti-proliferation financing, and Middle East Weapons of Mass Destruction Free Zone verification — as he did during his fellowship.