In 2005, Mathieu started working in court-appointed administrators firms (M. Chavaux, SCP Valliot Le Guernevé Abitbol) and law firms (Fried Franck LLP) before joining UGGC Avocats, he then founded his own law firm in 2018.
For the last 15 years, Mathieu has specialized in bankruptcy law both on behalf of company managers and takeover candidates.
In 2021, he joined Saul Associés to create and lead the Firm's Restructuring Department.
Mathieu assists managers and shareholders in dealing with their company's struggles both in pre-insolvency and insolvency proceedings. He also advises his clients on takeovers of distressed companies. He acts for creditors facing difficulties with their partners or on behalf of court-appointed bankruptcy practionners (administrators and official receivers) in the context of complex legal issues.
He holds a postgraduate Bankruptcy Law degree (DU du Droit des Entreprises en Difficulté) from the University of Paris 1 Sorbonne (class of 2008) and he successfully passed the French national exam to access the professional apprenticeship of court-appointed administrator in 2008.