Mathieu is the owner, with his husband Ilya Razykov, of Saga Bookstore in Montreal, a bilingual independent bookshop – the only one in Quebec to specialize in speculative fiction. He’s the coeditor of the SFF collection VLB imaginaire, publishing C.L. Polk, Mélodie Joseph, Su J Sokol, and more. He also works as a literary agent for Omada, where he specializes in SFF talents both in the literary and the audiovisual fields.