The series was first announced in April 2021 under the codename 'Graymail' as an unnamed espionage drama acquired by Netflix, with Entertainment One backing the production.

The show was created by Alexi Hawley, known as executive producer of procedural dramas like Castle and The Rookie, who also served as showrunner.

The project brought together an unusual mix of executive producers, including star Noah Centineo, director Doug Liman with his Hypnotic partners Gene Klein and Dave Bartis, and Adam Ciralsky and Charlie Ebersol of P3 Media.

Each episode title in the series is written as CIA-like initials representing an abbreviated line of dialogue from that episode, mirroring the many acronyms Owen Hendricks struggles to keep up with at the agency.

Principal photography for the first season took place in Sorel-Tracy, Quebec, and Los Angeles, running from October 25, 2021 to March 28, 2022.

Filming for the second season began on January 4, 2024, and took the production to Vancouver, Canada, and Seoul, South Korea.

Teo Yoo was announced as a new series regular for season two in December 2023, joining as South Korean NIS agent Jang Kyu.

The first season received a 68% approval rating on Rotten Tomatoes and a 59/100 on Metacritic, while the second season improved significantly to 87% on Rotten Tomatoes and 73/100 on Metacritic.