Meet our team

Mariia Matsepa and Oscar Butragueno founded Koroliuk Consulting. Oscar has 25 years of experience world's most remote areas in the design, implementation and monitoring, and evaluation of humanitarian programs. Mariia has 20 years of experience in Monitoring, Evaluation, and Learning (MEAL) activities and fundraising in Eastern Africa, Europe, and the Middle East. 

Oscar Butragueno

Oscar coordinated large and complex humanitarian emergencies and recovery programs in seven world regions over 25 years abroad in Europe, the Middle East, North and Latin America, the Caribbean, South Asia, and West and East Africa. He holds a Master's degree in Social Policy and Planning (LSE) and a Master's degree in Political Science and Administration (Complutense University), which included stays at the reputable faculties of Politics and Marketing in Bristol (UK) and The Hague (The Netherlands).

He is a disaster preparedness, emergency response, and recovery professional with diverse experience in human rights, social protection, migration, public health, water, sanitation, and hygiene. He is an innovator who implemented the humanitarian action performance system and related automated emergency response and preparedness plans. 

Oscar is an empathetic manager with the networking, leadership, and management skills to successfully lead teams in challenging working conditions. He possesses reliable skills in talent identification, recruitment, and staff development. He can lead teams by conceptualizing, analyzing, and presenting complex multi-sector issues and developing sound, action-oriented plans and protocols. 

His ability as a compact communicator and media skills led him to found Thrist4thrill, a company dedicated to promoting socially relevant films during the pandemic.

He also serves his community as a licensed coach with US Soccer, where he has inspired youth teams to develop team values, build their skills and ultimately prepare young people to be confident in their future career challenges, whether in sports, social, family, or otherwise, depending on where their unique talents take them. And catch a couple of league titles along the way or a good team performance to be proud of for the future. He is also a U.S. licensed referee; otherwise, he works on his performance methods.

Olena Domanchuck

Olena co-authored the Assessment of the National Perpetrators’ response mechanism in Ukraine (2021), commissioned to Koroliuk LLC by UNFPA in the framework of the “EU 4 Gender Equality: Together against gender stereotypes and gender-based violence” program, funded by the European Union and implemented jointly by UN Women and UNFPA.


Olena has the unique experience of dealing with domestic violence cases at the European Court for Human Rights level. For instance, Olena successfully provided documentation, accompaniment, and supervision of domestic violence through the Kyiv regional, appeal, and supreme courts, and subsequently, to the European Court for Human Rights, eventually succeeding in her case to be admitted to the European Court for Human Rights and winning the case.


Her legal expertise as a lawyer on domestic and gender-based violence cases encompasses actions such as assisting clients in preparing proper documentation that can be held in court, deposing victims before the police and courts, affording legal advice to victims leading to successful court settlements, and providing psychosocial support to fragile victims and referral to social services, including the Department for social services and the Department for child services.


Since 2016, Olena has successfully submitted circa 100 cases, with a 90% success rate. 

Mariia Matsepa

Mariia brings her in-depth expertise in Monitoring & Evaluation, both as an in-house specialist within UN structures and as an External Evaluator of technical assistance humanitarian and development projects. Mariia got a Master of Arts from the College of Europe and graduated in Political Science from the National University ‘Kyiv Mohyla Academy’. Mariia is also an aspiring singer with a keen eye for art galleries. Mariia is currently very busy with her professional and personal endeavors, but she does remain our top volunteer advisor and our source of inspiration.

And our other top contributors, which we will include in due time!