Reuben is an economist and climate finance expert specializing in international economics, climate risk, and sustainable finance. He is the founder of the Kenya Climate Directory and the Executive Director of Climate Shapers Africa Limited. He sits on the Steering Committee of the United Nations Environment Programme (UNEP) AgriFood Project in Kenya.

Reuben has consulted for various institutions including the World Bank, multiple UN agencies, Rockefeller Philanthropy Advisors, UNEP Finance Initiative, Central Bank of Kenya, among others. He has spoken at high-level forums convened by the International Energy Agency (IEA), International Emissions Trading Association (IETA), Glasgow Financial Alliance for Net Zero (GFANZ), Alliance for Financial Inclusion (AFI), among others.

He has published widely in platforms such as the Africa Policy Journal at Harvard Kennedy School, World Economic Forum (WEF), Centre for Economic Policy Research (CEPR), and Project Syndicate. He has won several awards, including the St. Gallen Wings of Excellence Award and the Rudi Dornbusch Prize in International Economics. He has written three book chapters and authored multiple articles and commissioned reports.

As an industry expert, he has trained 850+ professionals at management and senior management levels, delivering trainings in Kenya, Côte d'Ivoire, Senegal, Eswatini, and South Africa. As a subject expert on green financial regulation, he has trained central bankers from over 20 countries. He also served as a Senior Climate Risk Expert on the Central Bank of Kenya (CBK) technical assistance programme that developed the Kenya Green Finance Taxonomy.

Reuben holds a Master in International Economics from the Geneva Graduate Institute (Switzerland) and a Bachelor in Financial Economics from Strathmore University (Kenya). He is currently a PhD candidate in International Economics at the Geneva Graduate Institute. As an adjunct lecturer, he has taught climate finance courses at University of Cape Town (South Africa) and Strathmore Business School (Kenya).

An avid traveler, he has visited 22 countries.