Our Team

Sotiris Petropoulos

During my PhD studies, I came across the Civil Society and Nonprofit Organizations. Since 2009, I am focusing on the NPO ecosystem, in particular through the research program “Thales-Evaluation of Greek Nonprofit Organizations”. In 2012, I started organizing a series of capacity-building seminars directed to organizations throughout Greece. Having met people from more than 200 Nonprofit Organizations, I can maintain my positive attitude and smile since all the elements for fascinating initiatives are out there. My aspiration is to support as much as possible the Greek ecosystem.
Sotiris holds a Bachelor’s degree in Shipping, an MA in International Political Economy and a PhD focusing on Regionalism in the Developing World.

Alexandra Emirza

Deputy Director

The first contact with the NPO ecosystem starts with my participation in the high school environmental volunteer team. Upon completion of my academic studies, I worked in private and Nonprofit Organisations where I gained experience in conducting economic studies and mainly in the preparation, analysis and monitoring of programs funded by national and international donors. Since 2012, I have been a key lecturer in capacity building trainings and regularly I evaluate projects, since measuring social impact is a long standing goal. Being a HIGGS member I hope to put my knowledge and experience to the service of all those who try to make the world better.
Alexandra has studied Public Administration and holds an MSc in Health Care Policy and Management from University of Birmingham.

Aris Souras


After six years in a multinational company, I resigned in 2014 to co-create a startup in the area of music, while participating in the Athens Center For Entrepreneurship And Innovation |the incubator center of the Athens University of Economics and Business| as a Marketing & Communications Mentor. During the last years, I have been a key lecturer in the capacity-building seminars entitled “Planning, Implementation and Evaluation of Developmental Programs” offered to NPOs executives throughout Greece, organized by the University of the Peloponnese, with the support of the Stavros Niarchos Foundation. Working at HIGGS will enable me to offer program participants my knowledge coupled with my experience from the multinational field, the startup ecosystem and the NPO environment.
Aris has studied Political Science and Public Administration and holds an MA
in Marketing & Management from the University of Bradford.

Katerina Matiatou


I found myself in the ΝPO ecosystem by mere luck in 2008. Since then, luck has transformed to enthusiasm and love! Having acquired experience at the “Royal Academy of Arts”, “Special Olympics” and “Future Library”, my path led me to “Desmos”, where I became familiar with the vision and work of hundreds of Nonprofit Organizations across Greece, via the majority of Desmos’ nationwide programs. As part of HIGGS, I want to share everything I’ve learned with other organizations and help them to be effective and sustainable.
Katerina has studied Communication, Media and Culture and holds an MA in Cultural & Creative Industries.

Archonto Antonatou

Assistant Manager
Newsletter / Website / Research & Administrative Support

My work experience in 5 Nonprofit Organizations involved in different fields (refugees, education, vulnerable and socially excluded groups) and my participation at the Vodafone «World of Difference program» in 2015, helped me further understand the challenges that the organizations face in their attempts to achieve their objectives. Through my work at HIGGS, I hope to make a valuable contribution to the Greek NPO ecosystem by meeting their needs. I am glad to be part of a team with a common vision and the desire to “help those who help”!
Archonto has studied International Relations and holds an MSc in International Development.

Katerina Velliou

Assistant Manager
Events / Communications / Research & Administrative Support

Since 2012 I have worked in 3 Nonprofit Organizations with different scopes: environment, social vulnerability and education. My work consisted in supporting them in the areas of Administration, Marketing and Fundraising. In particular, my three-year experience in a newly established organization and my current contact with the organizations of HIGGS programs have showed me how much enthusiasm and sincere willingness there is in the Greek NPO eco-system, and how much need there is for training, networking and better coordination. As a member of the HIGGS group, I hope to stand by them, supporting their vision and strengthening their efforts.
Katerina has studied Law at the Democritus University of Thrace.

Katerina Kaisari

Assistant Manager
Fundraising/ Reasearch & Administrative Support

During my studies, I acquainted with the Third Sector that spurred my interest in working on this sector both at academic and professional level. In particular, I had the opportunity to come into contact with the Greek ecosystem of Nonprofit Organizations in terms of my master thesis, studying the relationship between the Greek state and NPOs in the face of the refugee crisis in Greece. As a part of the HIGGS team, I hope to significantly contribute to the development and sustainability of the ecosystem of NPOs in Greece.
Katerina has studied Political Science and Public Administration and holds an MSc in Crisis and Security Management. She is also a PhD candidate in the Faculty of Political Science and International Relations at the University of Peloponnese.

Marianina Karaiskou

Administrative Officer

Volunteering while studying made me realize the value of helping without discrimination as well as the need for organizations that serve this purpose. That was the reason that led me to look for an internship at the nonprofit ecosystem. This experience reinforced my belief that in today’s time the role of Nonprofit Organizations is crucial. I hope that as a member of the HIGGS team I will be able to contribute to their promotion and capacity strengthening.
Marianina is a senior student at the Department of Social Anthropology at Panteion University.