Kwek began writing as a student at Raffles Institution under the mentorship of writers like Alvin Pang and Aaron Maniam.
He has since published four poetry collections in Singapore and in the UK, namely They Speak Only Our Mother Tongue (2011), Circle Line (2013), Giving Ground (2016) and The First Five Storms (2017).
His work has also appeared in both Singaporean and foreign-based journals, including The Irish Examiner, Southword, The London Magazine, The North, and the Quarterly Literary Review Singapore (QLRS).
The poem was also adapted as a chamber opera by Daniel Bonaventure Lim at the Performing the Jewish Archives project at the University of Leeds.
Theophilus co-edited Flight, an anthology of poetry in response to the European refugee crisis, published by the Oxford Students’ Oxfam Group.