Merkley was born in Cambridge, Ontario, and studied at the University of Waterloo from 1998 to 2001, and employed at Engineers Without Borders Canada as the Chief Communications Officer. He worked for the City of Toronto and City of Vancouver in roles such as Director of Communications and Senior Advisor to the Office of the Mayor, leading the open government data initiative of Toronto mayor David Miller. In 2010, he moved to the Mozilla Foundation to take the role of Director of Programs and Strategy.