Reuben received his education at St Aloysius College and graduated in law from the University of Malta in 1993. He was admitted to the Bar in 1994 and has been a member of the Bar ever since. In 1998 he was elected to the Board of the Chamber of Advocates and was appointed its President in 2011, a position he held until March 2015, the maximum period allowed by the Chamber's statute. He is also the head of the Maltese delegation at the Council of Bars and Law Societies of Europe (CCBE). He is also a member of the International Bar Association.
He has served as a Director on the Board of the Malta Communications Authority, the national regulator responsible for electronic communications, electronic commerce and the postal sector, between 2001 and 2009. Between 2009 and 2011, he held the post of Chairman of the Malta Resources Authority which is the national regulator for energy, water and resources and is also responsible for oil exploration and climate change.
Reuben practises mainly in commercial and corporate law, financial services, debt recovery, data-protection and consumer affairs. He also sits as Director on various boards of commercial companies with a varied range of commercial interests and also serves as Company Secretary of a number of commercial entities in Malta.
His hobbies include photography, reading, IT and football.