[citation needed] In high school, he won the 2005 Sydney Morning Herald Young Writer of the Year prize for a short story called 'Bing Me', and went on to sign his first book deal in his final year of high school.

[citation needed] Kostakis scored his first publishing contract at 17, while still completing his final year of high school,[1] Newington College.

[2] He began work on a variant of Loathing Lola when he was 11 years old, and continued to refine it.

[4] The novel was a critical success, dubbed a "kickass debut", "a smart, sharp tale about fame, love and loss" by Dolly magazine,[5] "brilliant" by The Examiner,[6] "a promising debut from a young and talented Australian writer" by Danielle Trabsky at Australian Book Review, "polished" and "extremely funny" by Mike Shuttleworth at the State Library of Victoria,[7] and received many other positive reviews.

[14] On 1 July 2020 Kostakis became a mentor of Express Media's newly renamed Hachette Australia Prize for Young Writers and, along with Hachette head of children's publishing Jeanmarie Morosin, joined the judging panel for the prize.