Sylvain has held various positions both at the ICRC’s headquarters in Geneva and delegations. He worked as a Field Delegate in Colombia, as well as Operational Legal Coordinator in Myanmar. He has also worked as Legal Adviser and Program Manager with different non-governmental organizations and was lecturer and researcher with academic circles. Sylvain holds a Ph.D. in International Law from the University of Geneva. He has published several academic books and articles on International Humanitarian Law, human rights law, and the privileges and immunities of international organizations. He also contributed to the ICRC’s new Commentary on the Geneva Conventions of 1949.