Xavier worked at the Nuffield Trust as Senior Research Analyst from April 2011 until November 2012. He joined the Trust from his previous role as Information Manager for the Royal Marsden NHS Foundation Trust, where he led the team that was responsible for all management information reporting within the trust, as well as provision of financial and activity information to commissioners.

Prior to that Xavier worked at the Healthcare Commission where he focussed on using a wide range of qualitative and quantitative data to target regulatory activity such as inspections. He was also heavily involved in developing the use of quantitative information to help to monitor the performance of independent sector health care providers.