The cast of Roots were invited to take DNA tests, and Kirby's results came up as mostly West African with some South Asian and a small amount of European.
[12][13] That October, Kirby starred in an episode of the anthology series Black Mirror entitled "Men Against Fire", directed by Jakob Verbruggen.
[16] Kirby went on to star as Michael Garwick in the 2019 Sky One dystopian drama Curfew and Oliver Harris in the Italian series Devils.
[19] Kirby landed the role of Darcus Howe in the "Mangrove" installment of Steve McQueen's Small Axe anthology, which premiered in 2020.
In September 2021, it was announced Kirby would star opposite Delroy Lindo as both of Mr. Nancy's sons Charlie and Spider in the Amazon Prime adaptation of Neil Gaiman's Anansi Boys.