Giuseppe has been a full-time mediator since 1997, specialising in workplace and commercial cases. He was an online mediator for SquareTrade.com from 1999 to 2004 for resolving e-commerce related disputes arising out of eBay transactions.

Giuseppe has been mediator for the United States Postal Service for resolving workplace disputes (discrimination, harassment, supervisor vs employee disputes). On January 9, 2014 Leone participated in the first USPS mediation conducted online, with parties (Postmaster, employee and his union rep) in Guam, the mediator in Hawaii, and an EEO/ADR observer in Sacramento, California.
 

Giuseppe is founder and Project Manager of VirtualMediationLab.com, an online mediation project sponsored by the Association for Conflict Resolution Hawaii Chapter to teach mediators around the world how to add online mediation to their practice. 

Giuseppe is also a Team Member of the Online Peer Mediation Platform, an innovate project funded by the JAMS Foundation for middle and high schools. And he is working with a group of mediators in Nigeria to promote online mediation in Africa.