OPTIMA is a multi-stakeholder-led consortium with the vision that each and every patient should have access to the most up-to-date individualised treatments and to innovative therapies. In that perspective, we will design, develop and deliver the first interoperable and GDPR compliant European real-world oncology data and evidence generation platform, along with decision support toolsets for prostate, lung and breast cancer. By designing this platform from the onset based on the needs of the clinicians and patients in an inclusive and sustainable way, OPTIMA aims to strengthen shared decision-making based on innovative data and AI-driven technology and tools. To achieve our vision, we have united the key partners from other data-driven European wide oncology initiatives (PIONEER, EHDEN, HARMONY) in our project along with Europes leading clinicians in the fields of breast, prostate and lung cancer that all have leading roles in medical societies such as ERS, ESMO, and EAU. At the core of the OPTIMA project are the major guideline offices of the three indications, whilst the project is further strengthened by patient advocacy groups, well-known academic partners and 6 SMEs as partners covering the needed expertise to implement OPTIMA successfully. The platform will build on existing open source solutions such as the OMOP-CDM, tranSMART and OHDSI ATLAS whilst developing novel AI models based on federated learning to facilitate knowledge discovery. At the start of the project, we will already have access to datasets covering over 200M people in Europe, along with data from high quality patient cohorts for AI model building. Moreover, the platform will be hosted in-kind on existing infrastructure provided by Helmholtz Institute in Germany. Finally, OPTIMA envisions sustainability of its platform through a value-based approach with various business models for commercial users.