His career began in 1974 at the Record Plant Studios NYC, working with John Lennon.
Later, he became a staff engineer at the Record Plant, and later at The Hit Factory.
Panunzio has also produced, engineered and mixed artists including Bob Dylan, U2, Stevie Nicks, Black Sabbath, Ozzy Osbourne, Motörhead, Deep Purple, Aerosmith, The Who, Iggy Pop, Joan Jett, David Bowie, Tom Petty, and Paul Butterfield, among others.
[citation needed] Panunzio's experience also includes the making of motion picture soundtracks, such as Road House and Rattle & Hum.
In 2003, Panunzio joined Universal Music Group as Executive Senior VP, and Head of A&R for Geffen Records, where he oversaw the careers of Nelly Furtado, Weezer, The Pussycat Dolls, Rise Against and others on the Interscope/Geffen/A&M roster.