O-CEI overarching goal is to pilot the imperative of accelerating the uptake and upscaling of innovative Cloud-Edge-IoT solutions, strengthening Europe’s competitiveness and open strategic autonomy by orchestrating cross-domain data sharing, minimising energy footprint, stimulating multi-sided marketplaces, and promoting open standards for virtualisation and interoperability. For doing so, O-CEI will feed with such innovative technologies, and a comprehensive framework, to eight multidimensional real-world pilots framed in key strategic sectors: electricity grid, electromobility, software-defined vehicles, agrifood and agriculture, logistics and urban environments. It will swiftly create and implement innovative solutions across the cloud continuum; and effectively address the needs of existing and emerging individual and cross-sector business value chains. By designing blueprints and providing utilities beyond the SotA, O-CEI will help project stakeholders (and 32 Open Call awardees) to achieve challenging objectives. All pilots are formed by technical and stakeholder actors covering the necessary value chains, having an outstanding cross-domain unifying thread: energy flexibility.