Digital research platforms are increasingly expected to operate as open, inclusive, and sustainable infrastructures that enable meaningful engagement across disciplines and communities. Within this context, our work focuses on improving GoTriple, a multilingual discovery platform for Social Sciences and Humanities run by the OPERAS RI, by integrating new services co-designed with its research communities through the LUMEN and GRAPHIA EU funded projects. These projects aim to extend GoTriple’s capacity for collaborative knowledge exploration by developing novel tools for visualisation, annotation, and cross-domain discovery in four scientific domains—Mathematics, Earth Systems, Molecular Dynamics, and Social Sciences & Humanities. To achieve this, we adopt a participatory, human-centred approach that positions researchers not as passive users but as partners in shaping the next generation of a multidisciplinary open research infrastructure. Understanding user needs in such a complex environment requires more than standard usability testing; it demands trust, long-term engagement, and methods that capture how diverse communities make sense of design choices. In a distributed European consortium, we therefore used hybrid online and in-person co-design workshops where participants from different disciplines shared needs and collectively envisioned future GoTriple services. Our methodology draws on human-centred design and participatory research to rebalance the roles of researchers, designers, and platform users. Within the LUMEN and GRAPHIA projects, this approach supports the development of services that foster discovery, interdisciplinary exchange, and responsible AI integration. Early community involvement helps ensure that the resulting infrastructure is socially responsive, transparent, and aligned with real research practices. We operationalise this approach through a structured process composed of recruitment, communication, and translation of design artefacts. Recruitment is co-designed with partners to ensure openness and inclusivity. Snowball sampling through professional networks, flexible participation formats, and accessible sign-up workflows allow us to reach researchers across domains, career stages, and linguistic backgrounds. The GoTriple platform design is continuously updated to support transparency and evolving recruitment needs. Our communication strategy builds on insights from earlier semi-structured interviews and is iteratively refined. Research questions, personas, scenarios, workshop scripts, and design tasks are co-reviewed across all partner organisations. Pilot testing with external researchers ensures clarity, accessibility, and comfort—addressing elements such as duration of tasks, audio participation, help-seeking options, and accessibility requirements related to colour, fonts, and interface layout. Translation is essential in a project spanning diverse epistemic cultures and digital practices. Co-design workshops create a shared space to identify common challenges, explore perspectives through familiar metaphors, and generate ideas that can be integrated into GoTriple. Using human-centred design tools and a “How might we…?” approach, these workshops catalyse exploration of functionality, interfaces, and interactions, supporting sustainable platform evolution. Finally, through sharing and operationalising, we apply Thematic Analysis to produce cross-cutting insights representing the voices of participating communities. These themes feed directly into prototyping activities carried out with User Experience (UX) and Graphical User Interface (GUI) specialists in LUMEN and GRAPHIA, ensuring that all new GoTriple services are conceived with inclusivity, openness, and long-term sustainability at their core.