Guillaume joined Mazars in Paris in 1999 after graduating the Engineering Bachelor of Science from the Arts & Métiers engineering school, and after a specialized master from the HEC business school.
He moved to the Mazars Manhattan based office in 2008 where he became a Certified Public Accountant and made partner in 2011. He worked with public and private clients, in the insurance and luxury industry for the most part.
Guillaume moved back to the Paris office in May 2014. Also a certified French actuary and a French statutory auditor, he is now providing audit services to life and non-life companies, as well as consulting services to non-attest clients.
On the other hand, Guillaume is also the Head of the US Desk in Paris, which deals with US Auditing Standards and other SEC-related matters.
Since 1999, Guillaume served most of the largest insurance groups in France, such as AXA, SCOR, Groupama, Paris Re or Natixis Insurance.