In Sunset Boulevard, what is Joe Gillis's profession?

In Sunset Boulevard, Joe Gillis is a screenwriter.

Played by William Holden, Gillis is introduced as a down-on-his-luck Hollywood writer struggling to sell scripts and pay his bills. He becomes entangled with Norma Desmond, a former silent-film star who wants him to revise her grand screenplay about Salome and help engineer her return to the screen.

Gillis’s profession drives the plot. Because he can write and understands Hollywood’s commercial machinery, Norma sees him as useful; because he is desperate for money, he accepts her offer to work at her mansion. Their arrangement gradually becomes a coercive and morally compromised dependency.

The character is sometimes mistaken for a reporter or detective because he narrates the film and the story begins with a murder investigation. He is neither: Gillis is a professional scriptwriter whose failed career mirrors the film’s satire of Hollywood ambition, exploitation, and fading celebrity. He also secretly collaborates with Betty Schaefer on an original screenplay.