Following graduation from business school, he joined the private sector working for Petro-Canada and Comterm, a Quebec-based microcomputer and keyboard-terminal manufacturer and local-area-network software developer.

Scarpaleggia's involvement in politics began as a volunteer in the riding of Mount Royal during the 1981 Quebec election, working for the Liberal incumbent John Ciaccia, who was re-elected to the provincial legislature.

Following the election, which saw the separatist Parti Québécois elected for a second term, he remained active as a grassroots provincial Liberal organizer, notably serving as the youngest riding president (Mount Royal provincial riding association) in the Quebec Liberal Party at the time.

Prior to being elected, he worked from 1994 to 2004 as legislative assistant to Clifford Lincoln, a former environment minister in the Quebec government who then served, after entering federal politics, as parliamentary secretary to the Minister of the Environment and then as chair of the House of Commons Standing Committee on Canadian Heritage.

He holds a reputation as a dedicated constituency representative, close to his electors and focused on their political concerns and priorities.