Arditti was born in Geneva and grew up in Istanbul and moved to London in 1999. He graduated from the Royal Academy of Dramatic Art in 2004.
On the stage Arditti played Yossarian, the New York bomb aimer, in Joseph Heller's stage adaptation of his novel Catch 22 on a UK national tour directed by Rachel Chavkin.He is a regular performer at London's National Theatre, including roles in England People Very Nice (2009), Blood and Gifts (2010), Holy Rosenbergs (2011). In September 2017 he played Uri Savir in J.T. Rogers's stage play Oslo at the venue's Lyttelton auditorium, accompanying the production when it transferred to the West End in the following month.
In 2014, he played a goatherd in the Game of Thrones episode, The Laws of Gods and Men.
