We present the observable-by-design principle. We believe that the new generation of services, products, and environment management systems should be designed to adapt to changes. Therefore, they should be designed to be observable, and their design should proactively and reactively adapt to the changes observed both internally and externally. Two concrete examples illustrate the application of observable-by-design principle: (1) ship building and management, and (2) river dam water flow management. We believe that the observable-by-design principle can be applied in a large scale. In the long term, a new generation of observable- by-design infrastructures can be built that incorporates the sensing and adapting capabilities in their construction.