Having recorded demos for Thin Lizzy and the Stranglers, he became an engineer for Mutt Lange. With Lange he worked on the AC/DC albums "Highway to Hell" and "Back in Black", and the Foreigner album "4". On his own he engineered and produced the work of artists such as Iron Maiden, Krokus, Motörhead, Gary Moore, Cheap Trick, the Cult, and Marillion. He also recorded two albums for Buddy Guy - the Grammy winning "Damn Right I've Got the Blues" and the follow-up "Feels Like Rain". Platt also produced Rough Trade's very first label release, the 7" single "Paris Maquis" by French band Metal Urbain.