This study investigates how orchestrators of innovation ecosystems with social missions integrate public sector actors to achieve systemic impact. Using the Mojaloop Foundation as a single-case study, we explore the phased ecosystem orchestration process, focusing on financial inclusion in resource-constrained settings. Drawing on a rich dataset of interviews, archival materials, and field observations, we develop a process model comprising three phases: mobilization, capacity building, and global-local integration. Each phase addresses distinct challenges, including the liabilities of newness, smallness, and foreignness, as well as resource constraints and public sector hesitancy. Our findings highlight the critical role of phased, iterative approaches in navigating these challenges. In the mobilization phase, orchestrators leverage global reputations and development goals to establish legitimacy. Subsequently, the capacity-building phase empowers local stakeholders through training programs, partnerships, and knowledge-sharing platforms. Finally, the global-local integration phase bridges expertise and needs, fostering collaboration and enabling feedback loops to enhance ecosystem legitimacy and scalability. This research contributes to the literature on ecosystem orchestration, social entrepreneurship, and public-private collaboration by offering theoretical insights and practical guidance for orchestrators. By emphasizing the transformative potential of aligning global and local ecosystems to address grand societal challenges, the Mojaloop case underscores the importance of adaptability, trust-building, and collaborative strategies in advancing innovation ecosystems with social missions.