Castonguay's practice is based in new media and digital art, and his works exploit both obsolete technology and open source software. He was a founding member of the not-for-profit media lab Artengine. Elements, a recent installation, was shown at the Musee d'Art Contemporain de Montreal in 2006. His works are included in the collections of the Canada Council Art Bank, the Los Angeles County Museum of Art, the Montreal Museum of Fine Arts and the Canadian Museum of Contemporary Photography.