Achilleas has been working as a journalist for SKAI Media Group since 2006. He specializes in transport, telecommunications and in the privatization programme of Greece, which he has been covering since its launch, in 2011. He has also worked for the oldest newspaper printed in English, Athens News, for approximately three years, as a news and features writer. During the past seven years he has occasionally worked for BBC and RTE, reporting on the financial crisis and its effects in Greece. He began his career in London, working for several national newspapers, magazines and news agencies as a freelance journalist. His day to day duties included writing news and features, securing exclusive interviews, and pitching countless stories to editors of national newspapers and magazines.

His academic qualifications include a BA in Media Practices (Second Class, upper division) from the University of Bedfordshire, an MA in Journalism from Cardiff University, as well as an MA in Public Communication and Public Relations (awarded with merit) from the University of Westminster.