Sustaining Knowledge and Governing its Infrastructure in the Digital Age develops a profound reconceptualisation of contemporary knowledge production by demonstrating that knowledge no longer exists independently of the infrastructures through which it is produced, circulated, legitimised and preserved. Pierre Mounier and Simon Dumas Primbault argue that the digital transformation of research, scholarly communication and information systems has generated a new epistemic order in which platforms, repositories, metadata systems, protocols, identifiers and computational networks function not merely as technical supports, but as constitutive conditions shaping what knowledge can become. Drawing upon infrastructure studies, science and technology studies (STS), cyberinfrastructure theory and ecological approaches to information systems, the text defines knowledge infrastructures as robust sociotechnical assemblages composed simultaneously of human actors, institutions, standards, software, hardware and governance arrangements. Particularly significant is the authors’ insistence that infrastructures are not neutral containers of knowledge but politically performative environments embedding values, hierarchies and forms of institutional power. The article traces the genealogy of infrastructure from nineteenth-century engineering and Cold War logistics to contemporary digital epistemics, revealing how infrastructures progressively evolved from material supports into relational systems organising cooperation, interoperability and cognitive production itself. Equally illuminating is the ecological perspective advanced throughout the text, where infrastructures are conceptualised not as static objects but as dynamic processes sustained through maintenance, repair, adaptation and negotiation across heterogeneous communities. Through examples such as Open Science platforms, digital repositories and collaborative knowledge systems, the authors expose the tensions between openness and enclosure, visibility and invisibility, sustainability and extractivism that define contemporary digital scholarship. Particularly compelling is the argument that governance constitutes the central analytical category for understanding infrastructures because decisions concerning standards, funding, interoperability and platform control directly shape epistemic legitimacy and access to knowledge. Consequently, the text advocates an ecology of knowledge infrastructures grounded in resilience, diversity, anti-extractivism and participatory governance capable of resisting corporate monopolisation of scholarly communication. Ultimately, the article establishes that sustaining knowledge in the digital age requires not only technological innovation, but also the ethical and political reinvention of the infrastructures through which collective intelligence is organised, maintained and shared across increasingly interconnected societies.