This chapter highlights the pervasiveness of change in most developed systems, and the resulting implications on development practice. A key problem with developed software systems is the focus on discrete one-off development. Emphasizing continuity and evolution requires a way of distinguishing between systems that can be assumed to remain stable and those that continuously “live” and evolve in their environment. Developing systems that are expected to evolve calls for a dynamic activity of design that is responsive to changes in the environment. The chapter concludes by discussing the role of design in such environments and characterizing design as a complex, responsive and negotiated search for an acceptable, yet changeable trade-off. This is taken forward by highlighting the implications for the adoption of adaptive design in dynamic environments, thereby justifying the move from discrete and project-based software engineering to a more strategic, continuous and evolving discipline of adaptive design.