Barbagallo has originated roles in plays by Joshua Conkel, Casey Llewellyn, Normandy Sherwood, Trish Harnetiaux and many others.
He appeared as Yann Fredericks in the original cast of Harry Potter and the Cursed Child at the Lyric Theatre on Broadway.
His playwrighting credits include Grey-Eyed Dogs (Dixon Place), Saturn Nights (Incubator Arts Center), Good Year for Hunters (New Ohio Theatre), Karen Davis Does … (Brooklyn Arts Exchange), Joe Ranono’s Yuletide Log and Other Fruitcakes (Dixon Place), Sentence Fetish (Brick Theater), Melissa, So Far (Andy's Summer Playhouse) and My Old Man (and Other Stories) (Dixon Place).
He is a 2009 Soho Rep Writer/Director Lab alum, a 2012 Queer Arts Mentorship mentee, and a 2013 MacDowell Colony Fellow.
In 2015, Barbagallo was selected to participate in the Persona Seminar think tank at the New Museum and was invited to the Clubbed Thumb Early Career Writer’s Group.