Universal Cable Productions reportedly acquired the television rights to Karen M. McManus's debut novel in a competitive situation in September 2017, initially intending to release the adaptation on E! before the project moved to NBCUniversal and became Peacock's first pilot order in August 2019.

Showrunner Darío Madrona was hired after the success of his Spanish Netflix series Elite brought him several American TV offers; he was drawn to the novel's flawed, untruthful characters and its potential to explore themes of friendship, love and desire.

Madrona deliberately structured the first season to resolve its central mystery (who killed Simon) by season's end, believing viewers often lose interest in shows that drag out their main mystery across multiple seasons, even though other questions remained unanswered.

For season two, showrunner Erica Saleh (who replaced Madrona) chose not to adapt McManus's second novel because it follows a different set of characters, opting instead to continue the story of the original cast without a book to use as a blueprint.

The pilot was filmed in Vancouver, Canada in November 2019, but the COVID-19 pandemic forced production to relocate the rest of the series to New Zealand, where the east coast beaches were used to visually double for Southern California.

Producer Matt Groesch had to find new locations in Auckland, including AUT Millennium and ASB Showgrounds, to recreate the high school setting since the pilot's school scenes had already been shot elsewhere; Rangitoto College was used as the rival school.

A COVID-19 lockdown during production of the remaining season one episodes forced the crew to shift the final days of shooting to Ontario, Canada, before filming wrapped in late September 2021.

Despite generally positive reviews and a 91% approval rating on Rotten Tomatoes, Peacock canceled the series after two seasons in January 2023 because it failed to attract enough viewers, even though executives were satisfied with its creative quality.