[1] She has contributed to several publications, including BBC Science Focus magazine and The Daily Telegraph, and authored the book Big Data: Does Size Matter?.

Harkness has co-written and performed comedy shows related to science and mathematics, including collaborations with her mother Linda Cotterill and comedian Matt Parker.

[10] Harkness' work for BBC Radio 4 includes an afternoon play,[11] documentaries,[12][13][14][15] being a roving reporter for The Human Zoo[16] and presenting FutureProofing,[17] a series about the future potential of science.

In 1999 Harkness co-wrote a comedy with her mother Linda Cotterill, called No Future in Eternity, about an astronomer who shares a flat with two angels.

[21][22][23] In 2012 Harkness and fellow comedian Matt Parker co-wrote a comedy show called Your Days are Numbered: The Maths of Death.