Operator of the prototype Colossus and the "Mark 2" Colossi at Bletchley Park, Du Boisson is recognized for her role in the wartime codebreaking effort. She joined the WRNS in 1943 and was posted to Bletchley Park. In the Newmanry during the pre-Colossus period, she operated Heath Robinson; she then moved on to the prototype Colossus and the "Mark 2" Colossi. Finally, Du Boisson became a registrar in the Newmanry's "Ops Room", where she was responsible for distributing and tracking the tapes containing the encrypted messages.
The war over, she went into the Air Ministry as Controller of Typists and later became a senior administrator in the Ministry of Defence in Whitehall.
In "Turing's Cathedral" by George Dyson it is noted beneath a photo of Colossus at Bletchley Park in 1943: "Supervised by Dorothy Du Boisson and Elsie Booker, a coded sequence stored in an internal vacuum-tube memory is being compared with a sequence stored on external punched paper tape, scanned at high speed by photoelectric reading heads."
