For tackling complex global challenges such as climate change, this publication advises how a Gateway Process (GP) can help the Asian Development Bank’s developing member countries channel scarce public resources into viable, sustainable, and efficient infrastructure investments. Supporting ministries of finance and related agencies, this publication explains how GPs can enhance the preparation, procurement, and execution of public private partnership projects and traditional public investment projects. To advance the environmental, social, and fiscal priorities of diverse economies and build institutional capacities, the publication describes an adjustable GP model—allowing policymakers to develop bespoke GPs within broader public investment management strategies.