The authors discuss a large system transformation project they designed and implemented in Slovenia at the start of its independence in the early 1990s. Post-mortem insights are useful for practitioners who embark on similarly broad transformation processes. Design issues are discussed such as structuring the pre-contracting phase to guarantee inclusive stakeholder representation and participation throughout the transformation process and how intervention design needs to allow for experimentation and multi-stakeholder alliance building. Application of action research and action learning in a risk-averse environment typical of central governments helped create a sense of ownership, control, and collective accountability in the partner country.