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Our cross-sectoral experience and engaged team

joyn-coop combines knowledge from academia and the private sector with professional experience in selected development areas. Our team includes two founding partners and ten staff members with extensive expertise in specific issue areas. We also cooperate with a network of affiliated experts and other firms which complement our competencies and enhance our capabilities. Together we work in the spirit of joyoountu.

Founding partners

Christina Kükenshöner
Master of Public Administration; Dipl. OAWISS/Master-level studies in East Asia Science

Christina has professional experience working in both the public and the private sectors. She advises development finance institutions and foundations on the structuring of funds and financing initiatives. Her thematic expertise is centered around conflict & fragility and multi-stakeholder financing instruments. She is an experienced process facilitator and partner for strategic dialogue. She enjoys analytical challenges in strategy development and is passionate about joint problem-solving. Christina has served as a Management Consultant at McKinsey & Company and as a Senior Project Manager for Financial Cooperation at KfW Development Bank. She holds a Master’s Degree from the Harvard Kennedy School (short vita).

Dr. Christiane Ströh de Martínez
Dr. rer. pol./PhD in Economics; Dipl.VWL/Master-level studies in International Economics

Christiane combines her academic background with extensive professional experience in development cooperation. She has served as a visiting professor at several German universities, teaching a wide range of development-related subjects. Her consulting work focuses on inclusive finance and local economic development. Christiane enjoys participatory processes and the aspects of co-creation in strategy work. She is also experienced in leading change processes as moderator and process facilitator. In her PhD thesis in economics, she conducted extensive research on inclusive financial sector development and microfinance (short vita).

Core Staff

Rosa Eckle
M. Phil in Development Studies; B.A. in Economics and History

As project manager for health, education and water & sanitation projects at KfW Entwicklungsbank, Rosa has acquired first-hand experience of German Financial Cooperation’s sectoral approaches and working principles. Her thematic foci include supply and demand-side approaches to education, HIV prevention strategies and reproductive health. Recently, Rosa created a toolkit to conceptualize and implement scholarship, loan or voucher programs in education. Rosa holds an MPhil. Degree in Development Studies from Oxford University and completed her studies with a postgraduate training at the German Development Institute in Bonn (short vita).

Lina Ghosh
MA in International Development; BA in Social Sciences

Lina combines international work experience in both public and private sector. Amongst other, she did projects in the field of housing & infrastructure as well as renewable energy & climate change for different organization such as NGOs, think tanks, KfW development bank, EU and UN. As a consultant with McKinsey she consulted large private companies in the industrial and insurance sector. Having lived and worked in many different countries, she is fluent in five languages and has developed in-depth knowledge of the post-soviet region and South Asia. Lina holds a Master’s degree in International Development from Sciences Po Paris (short vita).

Caroline Gruber
MA in International Relations; BA in Political Sciences

Caroline has international work experience in development cooperation and the private sector. Her areas of expertise comprise livelihoods and rural development, sustainable management of natural resources, sustainable tourism management, facilitation of financial cooperation with NGOs and private-public cooperation. Caroline conducts feasibility studies, conceptual studies and facilitates workshops. As German and French native speaker, Caroline focuses on projects in French speaking countries. Caroline holds a Master Degree in international relations from the Political Science Institute of Aix-en-Provence (France) as well as a Master Degree in political science from the University of Freiburg (Germany) (short vita).

Markus Kaistra
MSc in Development Management; BA in Liberal Arts and Sciences

Markus’ consulting work focuses on topics of education, livelihoods development, business promotion and fragile- and conflict-affected states. In his work at joyn-coop, he has gained extensive experience with the approaches and processes of German Financial Cooperation and in the cooperation with NGOs. Markus conducts conceptual studies, feasibility and evaluation studies and facilitates workshops, frequently using participatory approaches. During his work, he draws on his hands-on experience in the Thai non-profit sector and his interdisciplinary academic background. He holds a Master’s degree in Development Management from the London School of Economics (short vita).

Corinna Mueller
MA in International Development Studies; BA in Economics and Human Geography

Corinna is an inclusive finance specialist. She has advised and supported public and private sector entities in Asia and Latin America, leveraging her interdisciplinary academic background and quantitative and qualitative research expertise. Her policy work with GIZ and financial regulators has promoted inclusive insurance markets in South-East Asia. She has advised commercial insurers as well as specialized social enterprises on business strategy and financial awareness. Corinna holds a master’s degree in International Development Studies (short vita).

Christoph Renken
Magister Artium / Master-level Studies in Political Science, Law and Comparative Religious Studies

Christoph is an expert for development projects in fragile and conflict affected states and for transitions from short to medium and long-term development. He has extensive experience with approaches and procedures of German Financial Cooperation. Christoph conducts conceptual studies, feasibility studies, peace and conflict assessments and evaluations. As a consultant for joyn-coop he inter alia developed methods and approaches to rapidly select and appraise NGO projects, prepared strategic studies on engagement in fragile states and conducted remote evaluations for inaccessible project areas by using online tools and managing local consultants. Christoph holds a Magister Degree in political science, law and comparative religious studies from the University of Munich (short vita).


Ricarda Bollmann
Master of Business Administration; Dipl. OAWISS/Master-level studies in East Asia Science

Based in Lüneburg, Ricarda is an experienced financial controlling and reporting practitioner. Over the course of her 15-year career, she has lived, studied and worked in Germany, Japan, Hong Kong, South Korea, Singapore and Saudi Arabia. With most of her working experience acquired in the semiconductor and financial services industries, she has broad knowledge of various accounting and reporting requirements. Ricarda holds an MBA from Heriot-Watts University and an MSc in Area Studies (East Asia) from the University of Duisburg.

Affiliated Experts

Bettina Bauer
Dipl. Verw.wiss./Master-level studies in Public Administration

Bettina has both academic and practical experience in issues of decentralisation and subnational governance. She also consults on crisis prevention, post-conflict reconstruction and violence prevention in urban agglomerations. Beyond project-related studies and evaluations, Bettina has been the author of numerous hands-on guidelines and issue papers for German Financial Cooperation. She has served as a project manager at KfW Entwicklungsbank, holds a master-level degree in Public Policy and Management from the University of Potsdam and completed her studies with a postgraduate training programme at the German Development Institute (short vita).

Marietta Feddersen
B.A. in Economic and Social Anthropology

Marietta has a thematic focus on inclusive finance and combines her professional experiences from public development cooperation and private impact investing. Her employment with GIZ and the alternative fund manager Finance in Motion has equipped her with extensive practice in conceptualization, management and evaluation of financial sector-related capacity building projects. As a consultant, she works on realizing Blended Finance instruments that combine investment and technical assistance to leverage impact in the fields of micro, small and medium enterprise (MSME) finance and education finance. She holds a combined master’s degree in economics and social anthropology and is certified in SME Finance. (short vita)

Stefanie Jung
M.Sc. Environmental Protection; Dipl.-Economist (Master-level studies)

Stefanie has served for several years as a project manager for development cooperation at KfW, as well as an advisor for the International Climate Initiative at the German Environmental Ministry. Her work as a consultant focuses on development challenges in education, social infrastructure, environment, and climate change as well as employment generation. She holds two master degrees (in Economics from FU Berlin and in Environmental Protection from the University Rostock) and has completed a post-graduate training course at the German Development Institute (DIE). Having worked in Latin America, the MENA-region, and South-East Asia, she is fluent in 4 different languages (short vita).

Martina Wiedmaier-Pfister
Master of Business Administration, Certified Banking Specialist

Martina has been working in financial systems development for more than 20 years. She is a Policy and Regulatory Consultant and advises national, regional and global projects, as well as microfinance institutions, central banks and supervisory authorities. Her focus is on rural finance and inclusive insurance. She has carried out numerous assignments in Africa, Latin America and Asia, focusing on the regulatory sphere and on market development strategies. During her 8 years as long-term expert in Asia and Latin-America, she has authored policy papers and research papers on responsible finance, regulatory frameworks and consumer protection, as well as country diagnostics studies, feasibility and evaluation reports (short vita).