This paper addresses the critical challenges faced by organizations in designing and managing digital ecosystems within the ongoing digital transformation. Previous research has made notable progress in tackling technical and infrastructural concerns yet practical implementation, value creation, the integration of diverse partners remain underexplored and difficult to operationalize. Existing design-oriented research methods, such as Action Design Research (ADR), provide a strong foundation but lack a stepwise, process-oriented approach that fully recognizes the active roles of researchers as facilitators, knowledge providers, and trust anchors in the context of digital ecosystems. Moreover, current methods do not sufficiently accommodate the heterogeneity of ecosystem partners and the emergence of scientific artifacts during ecosystem formation. To bridge these gaps, we propose the Testbed Research approach, an adaptation of ADR specifically tailored for the complex realities of digital ecosystem development. Drawing on empirical evidence from 30 ecosystem initiatives conducted between 2016 and 2026, we demonstrate the methodological innovations and practical benefits of Testbed Research. Our findings contribute to both theory and practice by offering a robust framework that supports sustainable value creation and the effective orchestration of digital ecosystems, ultimately bridging the divide between academic insight and organizational practice.