In 1994, Vassallo appeared in the movie "Blankman", opposite Damon Wayans, Jason Alexander, and Jon Pulito. This was followed by feature film roles in “The 4th Tenor” opposite the funny Rodney Dangerfield, “Just Married” opposite Ashton Kutcher and Brittany Murphy, and the drama feature “My Brother Jack” opposite Marco Leonardi of “Cinema Paradiso”. In 2004, Vassallo re-teamed with Damon Wayans for the feature film "Behind the Smile". In 2009, Joseph co-starred opposite Academy Award Winner Forest Whitaker and comedian Carlos Mancia in the comedy motion picture, “Our Family Wedding”. Just to mention a few, Vassallo’s television credits include guest appearances on Award-Winning Shows such as "Diagnosis Murder", "The West Wing", "Alias", "Damon", and recurring guest roles on "My Wife and Kids" In 2023, Joseph can be seen on two fresh television shows.  He plays the role of, Saro Vitelli on the hit show "The Offer" opposite Miles Teller and Juno Temple on the Paramaount+ streaming platform and in addition Vassallo plays the recurring role of Antonio Russo on the international hit mini-series, "From Scratch" opposite, Zoe Saldana for Netflix.