Your Team

Vassilis Antonas, Founder, Managing Director, Diploma Director
Executive Coach, Psychotherapist, Organisational Development Consultant and Course Director of Impact’s Diploma in
Executive Coaching and Organisational Development (AADCT), globally the first Coaching Training to receive
Accreditation from the Association for Coaching. Vassilis is the author of Coaching for Impact: The Evolution of Leadership, published by Routledge in 2017. He also serves as the Supervising Consultant for Winning Culture and other
organisations.
Impact’s Founder has consulted for over 70 Greek and Multinational companies, delivering tens of thousands of
consultation hours to leaders from all functions and industries. Clients include Microsoft, Allianz, Alcon, Stoiximan,
Vestas, Nike, Unilever and Abbvie.
From 1998 to 2001, he worked for the British NHS and served as Clinical Director for CAP London from 2001 to 2006, at
which point he returned to Greece and founded Impact. His vision is to craft the circumstances for pursuing excellence
for individuals and organisations: directly, by offering Executive Coaching and Organisational Development services and
indirectly through the Diploma.
Vassilis is also a published song writer, a senior martial artist, a free diver, former motorsport driver and a devoted world traveller.

George Diakonikolaou, Associate
George Diakonikolaou is the Managing Director of “Project Management Coach” LTD, delivering services to business clients in the fields of Project Management, Leadership, Coaching and Organisational Development. His clients include companies such as Cosmote, Romtelecom, Vestas, ENEL, EDF etc. George is a visiting Faculty, teaching Project Management in the International MBA in Athens and Brunel Business School, MBA in London as well as Bradford Business School. He has received his First Degree in Electrical Engineering and Computer Science in National Technical University of Athens and his M.Sc. and Ph.D. in Computer Science from University of Manchester Institute of Science and Technology.
George is the co-founder of the Greek Chapter of the Project Management Institute, a Certified Project Management Professional and a founding member of the Hellenic Coaching Association. He is also an NLP Trainer and Master Practitioner of NLP & Time Line Therapy®, a Master Practitioner of Hypnosis and an NLP Master Coach.
Currently, George is experimenting with the integration of Coaching, Organisational Development and Project Management in a field that he likes to refer as “Project Coaching”, an integrated model that achieves groundbreaking results in Strategic Projects, Programs & Portfolios, and executive teams’ performance.
George is a 2010 Diploma Alumnus.

Tereza Venetsanou, Associate
The Founder of Winning Culture and Impact’s Business Development Director, Tereza is a seasoned Executive Coach, Trainer and Organisational Development Consultant. In the past, she has held leadership positions, for over twenty years, in multinational corporations, such as Wind, Vodafone and Microsoft. She is currently also working internationally for Vodafone Group as a Sales Transformation Consultant.
Her qualifications include a BSc in Business Administration, a MSc in Marketing, a Post Graduate Diploma in Executive Coaching and Organisational Development, a Master Practitioner in NLP. In the context of her continuous professional development, she is currently working towards obtaining her MSc in Integrative Counselling and Psychotherapy. Tereza is part of the Assessor’s Team for the Association for Coaching and is currently on her way to securing her Master Executive Coach Accreditation from the same body.
Her combined experience and expertise render her equally capable of coaching senior leaders, training sales teams and optimising the operational and sales structure for small and medium businesses, through on the job mentoring and coaching.
Tereza is a 2019 Diploma alumna.