[1] After graduating, Day initially intended to obtain a master's degree in journalism, but was instead offered a job for the Evening Standard on the Londoner's Diary feature by Max Hastings.
The first episode featured Phoebe Waller-Bridge, and subsequent interviewees have included Gloria Steinem, Kelly Holmes, Nadiya Hussain, Bernardine Evaristo and Adam Buxton.
[8][9] Day's second novel, Home Fires (2012), details two connected women responding to the aftermaths of the First World War and the conflict in South Sudan, respectively, as well as the impact of the ageing of loved ones.
Viv Groskop in The Observer praised Day's writing and described the book as "a beautifully written novel whose quietly discomfiting tone stays with you for a long while afterwards".
[10] Day's third novel, Paradise City (2015), received positive reviews internationally, including praise by Charles Shafaieh of The New York Times, who called the novel's depiction of life in contemporary London as a "testament" to Day's skills as a writer, in addition to a positive review by Amanda Craig in The Daily Telegraph.
[13] Day's fifth book and first work of non-fiction was How to Fail: Everything I've Ever Learned from Things Going Wrong, a tie-in with her podcast which was published in 2019 and received a positive review from The Sunday Times.
[16] Day explored the issue of motherhood not being possible by choice and society's perspective of failure with Dr. Rangan Chatterjee on BBC Radio 2 show.