The RESONANCE project develops an innovative software framework that provides means for rapid development and plug-and-play deployment of standard-compliant Customer Energy Manager (CEM), Resource Manager (RM), and their aggregation solutions. The CEM, specified in the EN 50491-12 standard family, is the next-generation demand-side flexibility management (DSFM) solution in Europe. CEM is a software agent that automates DSFM by interacting with smart appliances (represented by RMs), aggregators, and the markets to maximize customer benefits. According to the new EN 50491-12-2 standard, CEMs are envisioned to 1) provide a more deterministic demand response, and 2) be able to optimize consumer benefits with respect to multiple incentives and optimization targets. To achieve this, there is a need for accurate models of flexible assets (smart appliances) and model predictive control techniques to automate the decision-making within the customer premises. The RESONANCE Framework will facilitate the adoption of CEMs as the next generation DSFM system by significantly reducing the development efforts and costs. This is achieved with 1) a standard-compliant and modular system architecture, and 2) an innovative modeling pipeline that combines automated machine learning (AutoML) with physics-based modeling to provide accurate and robust models of flexible assets with minimum effort. The project brings together 19 partners (including a cluster with 40 organizations) with inter-disciplinary expertise and forms a basis for a cross-sector energy ecosystem that significantly contributes to the mobilization of DSFM at a large scale. Large scale piloting in six member states with a variety of consumer sectors, flexible assets (e.g. electric vehicles, HVAC systems, and white goods), stakeholders, and market settings (including sector integration with district heating) is utilized for demonstrating and validating the scalability and replication potential of the solutions.