<p>Boundary resources (BRs) designed to increase complementor satisfaction are essential for value co-creation in platform ecosystems, as complementors are not subject to the hierarchical control of a platform provider. Only satisfied complementors will engage in the development of innovative complementary solutions based on a platform. Ensuring this is no easy task for platform providers facing inter-platform competition, while existing research neglects complementor satisfaction as a target variable for platform providers to navigate the (re)design of BRs. To address this problem, the paper reports on an echeloned Design Science Research (DSR) project in the Industrial Internet of Things (IIoT) domain, which resulted in a method to align the (re)design of BRs with complementor satisfaction. Service quality techniques are used to obtain complementor feedback on the perceived quality of BRs, to assess issues and their impact on complementor satisfaction, and to prioritize measures that contribute most to complementor satisfaction, ultimately leading to increased complementor engagement. The method is theoretically grounded in the Expectation‐Confirmation Theory and draws on rich empirical data from the Siemens MindSphere ecosystem. It is instantiated as a prototype and evaluated in 12 focus groups. The method helps platform providers in the IIoT domain navigate the design of rich BR portfolios despite the dynamics of platform ecosystems in the IIoT, and advances research on platform governance.</p>