Mat works at The Filament Group in Boston, a company that designs engaging sites and apps for mobile, tablet, and desktop platforms. He is a designer and a developer who occasionally works independently with big-time clients like The Boston Globe. Mat also regularly writes articles for the A List Apart blog.

He is a member of the jQuery Mobile team, and also an active member of the open space community at movethewebforward. In addition, Mat chairs the Responsive Images Community Group.