Mr Sordet graduated from the École Nationale des Chartes in 1997 with a thesis on the history of bibliophilic practices (L'Amour des livres au Siècle des Lumières : Pierre Adamoli et ses collections) - awarded the Auguste-Molinier prize -, and later followed to join the École Nationale Supérieure des Sciences de l'Information et des Bibliothèques.
In 1998, he joined the corps of library curators and was assigned to the Sainte-Geneviève Library, where he headed the Reserve Department from 2003 to 2010. In 2011 he was appointed director of the Mazarine Library.
He taught history of books and libraries at the University of Paris XIII (1999-2006) and at the École Pratique des Hautes Études (2007-2009). He has been in charge of training in the field of written heritage at the École Nationale des Chartes, the ENSSIB, the Centre d'études supérieures de la Renaissance and the Centre de formation aux carrières des bibliothèques Mediadix.
He is editor-in-chief of the journal Histoire et civilisation du livre, a member of the Centre Jean Mabillon, the scientific council of ABES, and the Board of Directors of the Consortium of European Research Libraries [archive] (CERL).