Coulier graduated in September 2011 and used his 'Flemish Film Fund Wildcard' to create his first professional short 'Mont Blanc'. This short was produced by Dirk Impens for Menuet Films and was coached by Felix Van Groeningen, known as the director of 'The Misfortunates' and 'The Broken Circle Breakdown'. 'Mont Blanc' was selected in April 2013 for the Cannes Film Festival in the Official Shortfilm Competition. In 2014 Coulier completed writing & directing the fiction series 'The Natives' (Bevergem) for CANVAS. It was highly welcomed and appreciated by the audience with high ratings. The series won several Flemish television awards and was selected for the BANFF Rockie Awards for Best Comedy. In 2015 Gilles continued working on the script of his first feature ‘Cargo’ for De Wereldvrede. He participated at the 2016 Torino Film Lab. In 2016 he completed the shooting of ‘Cargo’, which was released in 2017. Gilles is currently directing the television series ‘De Dag’ for production company Woestijnvis and is writing a new fiction series ‘The Year of the Tiger’ for De Wereldvrede.