Sy was appointed as an expert adviser to the United Nations Development Programme and later headed the Commission for Decentralization and Institutional Reform in Mali.
He served as Minister for Territorial Administration and Local Communities under President Alpha Oumar Konaré.
He is the founder of the Centre for Political and Institutional Expertise in Africa (CEPIA), a consultancy service which he has also directed since January 2004.
In May 2005, Sy was awarded the King Baudouin International Development Prize "for the strength of his vision and the courage of his convictions on the subject of governance in Africa, and for the originality of his campaigns in Mali by which, through a participatory process of decentralization and the organization of transparent elections, he has succeeded in creating an environment conducive to a better public administration and increased stability, two conditions that are crucial for development.
"[1]The Baudouin prize was worth 150,000 Euros and Mr Sy says he will spend it on his organisation, CEPIA.