The character of Sully was originally written as an Asian but when writer Ronan Bennett and director Yann Demange saw Kano's audition tape, they happily changed the character's ethnicity.
Since his acclaimed debut in Bullet Boy (2004), Ashley Walters had deliberately shied away from any roles that involved gangsters and drug-taking. However, when he heard of the caliber of Ronan Bennett's script, he revised that stance.
This was originally commissioned for the BBC who balked at the amount of violence and profanity in the original script. Channel 4 decided to pick up the option before dropping it after two seasons, only for Netflix to take on the project for another three seasons.
Northern Irish-born writer Ronan Bennett has lived in Hackney, London for a period of time. He got the inspiration for the show when he observed a young boy dealing drugs in his local supermarket. Along with his friend Gerry Jackson, he started interviewing drug dealers in his local area to get a better picture of the process involved.
This first season aired over four consecutive nights on its original home of Britain's Channel 4.