Costas has been involved in ELT since 1998. He was trained and educated in the US where he gained his BEd from Concordia College, Diploma in TESL and attended a professional course in Multiple Intelligences at Harvard Grad. School of Education. He holds an MA in TESOL from Middlesex University, London. He has taught teenagers and young adults for the last ten years and worked as an exam supervisor for Cambridge ESOL.
Costas is currently an ESOL lecturer at IST College, University of Hertfordshire and a teacher educator at PROFILE. He participates as a tutor in the annual ELT methodology workshop of the English Faculty, University of Athens.
An active member of TESOL Greece, he served as chairman of the association for two years from 2008 to 2010.