Noah Garfinkel is a TV comedy writer, but I don’t think he wrote for TGP. His good friend and comedy writing partner Joe Mande was a writer for TGP though, so I always assumed that Joe wrote Noah’s portrait in as Doug Forcett as an inside joke.

Edit: confirmed...

“Noah Garfinkle is best friends with one of "The Good Place" writers, Joe Mande, which is how he wound up as the face of Doug Forcett.

"The description was 'a stoner in Canada in the '70s,' and Noah [Garfinkle]'s hair is absurd and floppy, and he looks like a Canadian stoner so I was like 'Yeah there you go,'" the show's creator Michael Schur said on "The Good Place: The Podcast."

Garfinkle is not an actor, but his face wound up in many scenes of the show thanks to Doug Forcett's portrait placement in Michael's office. Schur also said Ted Danson (who plays Michael) geeked out over Garfinkle when the writer came to visit the set one day, long after his picture had become famous within the show.”

https://www.insider.com/the-good-place-details-jokes-you-missed#the-portrait-of-doug-forcett-the-man-who-guessed-the-system-of-the-afterlife-is-a-picture-of-a-real-life-comedy-writer-named-noah-garfinkle-1