A human-geographer by training, Mathew is an expert on Water-Energy-Food (WEF) Nexus interactions and has experience of undertaking policy-relevant research, developing curriculum and delivering courses at both undergraduate and graduate levels in Canada, Netherlands, United Kingdom and Germany. As head of the Capacity Development and Governance Unit, he led the development of the first strategic plan of United Nations University (UNU-FLORES, Dresden, Germany), managed UN programmatic audits, launched cooperation with GIZ on the Nexus Observatory and established the Africa Points of Excellence (APE) consortium on drought risk monitoring based on agreements with governments in Tanzania, Malawi and Ethiopia. He spearheaded collaboration with UNHABITAT to organize regional dialogues in Vietnam, Jordan, and Brazil that facilitated the development, pilot-testing and validation of a monitoring methodology for Sustainable Development Goal (SDG) target 6.3. His contributions have been recognized through invitations to serve on international conference advisory boards, develop background papers for the Consultative Group on International Agriculture Research (CGIAR) and the recent award of a USD 1.8 million Belmont Foundation grant for research on integrative modelling tools and methods.