He served both the criminal as well as the civil side of the department, but his forte was civil law where he was handpicked to lead the State in several important landmark cases, including appearing in the 13th Amendment Case before the Supreme Court as Junior Counsel to the then Attorney General.
Shibly Aziz represented Sri Lanka in a number of international fora, including as the Chief Delegate at the second International Air Transport Conference 1980 ICAO held in Montreal and as a member of the Sri Lanka Delegation to the Conference of the Attorneys General of Asia and the Pacific, held in Colombo in 1985 and in Seoul in 1990.
Shibly Aziz also served as a consultant in International Relations and Legal at Airlanka Limited, the national carrier, from 1990 to 1994.
Recently, he participated in two high profile and prestigious international arbitrations, both in the capacity of an expert witness.
The first set of arbitrations was conducted in Singapore and London with respect to three claims made by international banks against the Sri Lanka Government arising out of hedging operations entered into by the Ceylon Petroleum Corporation.
The other was an international arbitration conducted in Singapore between the Maldivian Government and GMR, an airport developer in India.
Representing the interests of almost 15,000 lawyers in the country as President of the Bar Association of Sri Lanka, Shibly Aziz was keen to develop the image of the Sri Lankan legal system domestically and internationally as a credible, efficient, and transparent system.
With the help of United Nations Development Programme (UNDP), Shibly Aziz and the executive council of the Bar Association facilitated the development of courtrooms outside of Colombo, organised skills development opportunities for court staff, and facilitated a number of national and international conferences and seminars to enhance the professional expertise of lawyers across districts and to reinforce a positive image of the country's legal system among international bar associations.