Óscar is a senior associate at Rato, Ling, Lei & Cortés in charge of the Portuguese desk, and is a member of the Macao Lawyers Association, the Portuguese Bar Association and the Hong Kong Institute of Arbitrators (HKIA).

Before joining the firm, he was senior legal counsel for Melco Entertainment and other law firms in Macao. He was also a legal consultant for the Porto City Hall, for the Portuguese National Traffic and Transportation Department, and for the Honorary Consulate of the Republic of Guinea Bissau in Portugal.

He is a member of the Scientific Counsel of the Rui Cunha Foundation, a lecturer and consultant at CRED-MD – Center for Reflection, Study and Dissemination of Macao Law, and a visiting lecturer at the University of Saint Joseph, Macao.

Óscar is also a frequent speaker at gaming and non-gaming conferences around the world and is the author of several legal publications on gaming and non-gaming law and is also lecturer of Gaming Law at the Portuguese Catholic University (Lisbon School).