[5] He moved to Talkback Thames for four years,[6] working as a story producer on the Five soap opera Family Affairs, where he was taught to storyline by Ian Aldwinckle.
[9] He created the storyline in which the Muslim character Syed Masood struggled to reconcile his faith and sexuality, and his relationship with Christian Clarke,[10] as well as "The Secret Mitchell" and the "Who Killed Archie?"
The company is run by former EastEnders executive producer Diederick Santer, who commented: "Dominic is a brilliant and original talent, bursting with great ideas and gripping stories.
Many of EastEnders' best storylines and characters of the last few years have come directly from his imagination and design, and he played an integral part in conceiving and plotting the hugely successful 25th anniversary episodes.
Working on EastEnders has enabled me to create some fantastic storylines and characters that have been received so well but after four-and-a-half years of life in Walford, I feel that it is time to move on and try something new.
"[6] On 29 July 2013, it was announced that Treadwell-Collins would be returning to EastEnders as executive producer, taking over from Lorraine Newman, who resigned from the role after sixteen months on the job.
His first major cast change was to introduce Shirley Carter's (Linda Henry) extended family, who took over The Queen Vic – her brother (later revealed to be her son) Mick Carter (Danny Dyer), sister Tina (Luisa Bradshaw-White), Mick's common-law wife Linda (Kellie Bright)[12] and their children Lee (Danny Hatchard), Nancy (Maddy Hill) and Johnny (Sam Strike).
[16] Other major characters introduced by Treadwell-Collins include Dot Branning's (June Brown) grandson Charlie Cotton (Declan Bennett),[17] Pam (Lin Blakley) wife of established recurring character Les Coker (Roger Sloman), Donna Yates (Lisa Hammond), Vincent Hubbard (Richard Blackwood) as Kim Fox's husband, Claudette Hubbard (Ellen Thomas) as Vincent's mother and Donna's adoptive Mother, and the Kazemi family - Kush (Davood Ghadami), Carmel (Bonnie Langford) and Shakil Kazemi (Shaheen Jafargholi).
[38] Whilst at Blueprint, he developed and produced A Very English Scandal for the BBC and Amazon, starring Hugh Grant and Ben Whishaw, written by Russell T Davies and directed by Stephen Frears, winning Golden Globe, Emmy, Critics Choice, Rose D'Or, RTS and BAFTA awards.
[citation needed] In 2022, he wrote and produced Holding for ITV and Virgin Media, based on the novel by Graham Norton and directed by Kathy Burke.