In a world-class fundamental physics research organisation, driving a career development project can be an energising, but also a daunting project to handle. But we took on the challenge: to design and develop a learning framework to address the ”what” and the ”how” of a career conversation at CERN. The complexity of the environment and the diversity of the audience and stakeholders are two of the major milestones of bringing the project to life. The first milestone is convincing the management of the importance and necessity of a career conversation. The second is attracting the CERN community focused on high-level technical and academic work to that conversation.  The case study will present the context and challenges. It will focus on the framework, key milestones, the process, and potential outcomes of the career conversation at CERN and share a two-year journey and learning experience for the whole organisation.