Cortini was born in the Italian city of Bologna and raised in Forlì. Sometime around 1998, Cortini moved to the United States to study guitar at the Musicians Institute, where he met Swedish guitarist Pelle Hillström. After graduating he began focusing on keyboards and synths.
While briefly teaching at the Musicians Institute, he saw an ad for open auditions for Nine Inch Nails; after impressing [[Trent Reznor]] in his audition, he was brought on board to form the live band for the 2005 [[Live: With Teeth]] tour and has been a member of the band ever since. On December 13th, 2008, Cortini posted a blog on Modwheelmood's MySpace account stating that he is leaving the band and that the other members had known of his decision for some time. Cortini has shared songwriting credits with Reznor for several songs on ''[[Ghosts I-IV]]'' and "[[The Eater Of Dreams]]". He appears in the [[Nine Inch Nails music videos|NIN music videos]] for "[[The Hand That Feeds (song)|The Hand That Feeds]]" and "[[Survivalism (song)|Survivalism]]". In 2017, he appeared as part of Nine Inch Nails (in this case consisting of Trent Reznor, [[Robin Finck]], [[Mariqueen MaandigReznor]], [[Atticus Ross]], Cortini and Joey Castillo of [[Queens Of The Stone Age]]) in an episode of the reboot of ''Twin Peaks''.
Cortini is also the frontman of Los Angeles-area band [[modwheelmood]], which he leads with Hillstrom. The band is signed to fellow NIN bandmate [[Aaron North]] and Travis Keller's record label, Buddyhead. Prior to forming modwheelmood, Cortini acted as touring guitarist for The Mayfield Four.