This study aims to generate a systematic understanding of how digital platform firms can attain platform leadership. We explore the question by casting a boundary management lens over the complex network of interactions on a digital platform. Firms are faced with various boundaries-boundaries of efficiency, competence, power, identity, and ties-and must carefully address tensions within diverse groups of actors with their own interests. We conducted an in-depth case study on China's largest online ticketing firm and established two contributions for attaining platform leadership. First, we conceptualized the development of a digital platform as a set of technology-based boundary management mechanisms (functional multiplexing, scope expansion, community curation, actor empowerment, and positional escalation) that includes a combination of boundary spanning, erecting, and reinforcing. Second, we uncovered the network dynamics of a digital platform by explicating the synergies and tensions of boundary management. Considering our novel findings, this study offers managerial and design guidelines for a digital platform by advocating an integrative view of boundary management. We present a multidimensional framework that includes five boundaries and four types of networks (dyadic, interconnected, intraconnected, and external) for future analysis of networks built on digital platforms.