Léonie is Director of TetraLogical; a member of the W3C Advisory Board; co-Chair of the W3C Web Applications Working Group; and a member of the BIMA Inclusive Design Council.

Amongst other things, Léonie is co-organiser of the Inclusive Design 24 (#id24) conference; co-author of the Inclusive Design Principles; and mentor to young people interested in the fields of accessibility and inclusive design. She is also a Microsoft Most Valued Professional (MVP).