As the research and work on educational ecosystems has grown, we now recognize a growing global trend that has positioned “intermediary organizations” in an oversized ecosystem role. Through their direct work with schools, especially the most vulnerable schools, these organizations – which include NGOs, philanthropies, and for-profit agencies – straddle the larger ecosystem and the local schoolhouse, becoming conduits of external leadership resources into schools. In this report, the authors unpack their research into mature non- system intermediary organizations and their important role as an educational ecosystem builder. By exploring the activities and relationships of these organizations within the broader educational ecosystem, this research also sheds light on how other similar organizations may better consider and gain access to the kinds of ecosystem relationships and resources that are likely to prove important to their work and have a positive impact on schools and students.