Casting Penn Badgley was a meta-choice; he previously played Dan Humphrey in Gossip Girl , a character also revealed to be an "omniscient" stalker figure.

He follows her home, watches her through her street-level window, and eventually breaks into her apartment to snoop through her personal belongings and laptop.

Joe stages a rescue after Beck falls onto the subway tracks while intoxicated, a dramatic scene added for the TV adaptation to heighten the tension.

The show uses Penn Badgley's internal monologue to create a jarring contrast between Joe's outward "nice guy" persona and his delusional reality:

The pilot episode of (S01E01), titled "Pilot," serves as a chilling "horror meet-cute" that subverts traditional romantic comedy tropes. It introduces Joe Goldberg, a bookstore manager whose infatuation with aspiring writer Guinevere Beck quickly escalates into a dangerous obsession. 🕵️ The Stalker's Playbook

The episode establishes Joe's "slippery slope" behavior, showing how he uses technology and proximity to infiltrate Beck's life:

Joe identifies Beck's "douchey" on-again, off-again boyfriend, Benji, as a hindrance. By the end of the episode, Joe lures Benji to the bookstore basement and knocks him unconscious with a mallet. ⚖️ The Duality of Joe Goldberg