In complex systems development, project management is a key factor for innovation, for bringing together system capabilities to actually working systems and taking them to the customer. The critical question then is: How can successful project management in this field be conceptualized, practiced, and understood? In the extant literature, there is a plethora of suggested tools for advanced planning and scheduling, for system decomposition and modularization, and for reducing interdependencies and avoiding errors. There is also a growing criticism of these “planning approaches,” suggesting various contingency and flexibility approaches, to reflect and adapt to complexity and change. This critique, however, tends to lack grounded suggestions for effective managerial practices and does not distinguish between general flexibility needs and specific project structures required to make complex systems development at all possible. This article centers on the development of large, complex systems with an empirical focus on the telecom industry. Key challenges here, it is argued, are to understand complexity, reduce complexity, and rapidly act on the consequences of complexity to ensure timely delivery of reliable and predictable systems to highly demanding customers. To cope with these challenges, a set of innovative practices has been developed within Ericsson, a world leader in mobile network systems. We focus on three such practices, which together represent examples of a “neo-realistic” approach to project management: (1) lagomizing, a top-down redefinition of project goals to reduce complexity and transform expectations; (2) organic integration, an articulation and visualization of a shared understanding of system capabilities; and (3) Systemakut, the Systems Emergency Ward, a real-time, high-visibility agora for managing integration, handling errors, and making swift decisions and in public. The study is based on a research methodology involving knowledge coproduction, where the team of authors represents both academic knowledge and practitioner experience of managing innovations in complex systems development projects.