Platt was a business-affairs lawyer for (ICM) In- ternational Creative Management's superagent Sam Cohn, laying the essential groundwork of entertainment contacts.
His films include Legally Blonde (2001), Wanted (2008), Rachel Getting Married (2008), Nine (2009), Scott Pilgrim vs. the World (2010), Drive (2011), The Girl on the Train (2016), and Cruella (2021).
The film was controversial and accused of having a political agenda and fictionalizing the events leading up to the September 11, 2001 attacks, especially those involving the Clinton administration.
In 2021 he produced a film adaptation of the musical Dear Evan Hansen (2021) which featured a leading performance from his son Ben Platt, who originated the title role on Broadway.
Platt has produced numerous productions on the Broadway stage with his first official credit being Wicked earning his first Tony Award for Best Musical nomination.
[11] Platt and his wife Julie (née Beren) also a Penn graduate and trustee of the university,[12] live in the Los Angeles area.