Olivier is actively involved in numerous leading professional organizations and holds several distinguished positions within the valuation and financial expert community. He serves as President of the Association Professionnelle des Experts Indépendants (APEI) and Honorary President of the Compagnie Nationale des Experts Comptables de Justice (CNECJ). He is also a member of the Standard Review Board of the International Valuation Standards Committee (IVSC), the Compagnie des Conseils et Experts Financiers (CCEF), the Société Française des Évaluateurs (SFEV), the Valuation Commission of the Compagnie Nationale des Commissaires aux Comptes (CNCC), and both the Compagnie Nationale des Experts Judiciaires en Finance (CNEJEF) and the Compagnie Nationale des Experts Judiciaires en Finance et Diagnostic (CNEJFD). In addition, Olivier serves as a guest lecturer at the École Nationale de la Magistrature (ENM), where he delivers continuing education courses to magistrates.

Throughout his career, Olivier has advised clients on a wide range of complex financial and legal matters. His areas of expertise include acting as an expert witness and financial advisor in litigation, arbitration, liability guarantee disputes, and damage quantification assignments; providing corporate finance and business valuation services such as M&A support, independent valuations, business plan reviews, and impairment testing; conducting legal and contractual audits; and serving as an auditor for contributions in kind and merger transactions.