Sarah Catherine Hook, who plays Juliette, is actually months older in real life than her costar Gracie Dzienny, who plays her older sister Elinor in the series.
Executive producer and author of the original short story that inspires this series, V.E. Schwab described it as "Buffy the Vampire Slayer (1997) meets Killing Eve (2018)".
Sarah Catherine Hook read Sheridan Le Fanu's "Carmilla" (one of the earliest works of vampire fiction) to prepare for her role. Imani Lewis has cited Blade (1998) and Buffy the Vampire Slayer (1997) as an inspiration.
Vampires cry tears of blood in this series, similarly to the "Vampire Chronicles" and "Southern Vampire Mysteries" series of novels which, respectively, inspired Interview with the Vampire (1994) and True Blood (2008).
In the 3rd episode, Juliette can be seen sat next to an image of a butterfly and First Kill is set in Georgia. In real life back in 2018 it was reported that pest species Ricania simulans dubbed 'Vampire Butterfly' originated in Georgia and spread causing issues to tea plantations around the world. The species was named Vampire Butterfly because they suck the water out of plants, like a vampire sucking blood.