[1] He has worked with such artists as Hozier, PJ Harvey, Local Natives, U2, Depeche Mode, Editors, Glasvegas, The Courteeners, The Horrors, The Pains of Being Pure at Heart, Bell X1, Delorentos, Soulsavers, Soulwax and Sneaker Pimps.
Kirwan worked as an assistant engineer at Windmill Lane Recording Studios from 1992 to 1995.
Within his first year he worked on the U2 album Zooropa and then went on to work with producers such as Flood, Brian Eno, Steve Lillywhite, Stephen Street, Geoff Emrick, Nellee Hooper and Don Was.
He also worked with artists such as PJ Harvey, The Cranberries, Simple Minds, Kris Kristofferson, Willie Nelson, Elvis Costello and Sinéad O'Connor.
He then moved to London as a freelance engineer, producer and mixer and worked there for ten years before he relocated to Berlin, Germany.