The Digital Society is increasingly characterized by an ecosystem of smart, sociotechnical applications, such as smart grids, smart homes, smart cars, and so on. These applications are embedded in a social context with people “in the loop.” They are fully networked and saturated with sensors, and they use artificial intelligence for context-awareness and adaptivity. Unlike biological ecosystems, each application, and indeed the ecosystem itself, is critically dependent on humancentred, mutually agreed upon, conventional rules or norms for its effective and efficient operation. Therefore, developing socio-technical (eco) systems raises three major engineering challenges, but offers important new opportunities for successful collective action. The first challenge consists in modeling, understanding, and developing the interrelated processes behind the formation, selection, and adaptation of the systemic rules, since these are essential for ensuring desirable macro-level outcomes and avoiding detrimental ones. This may include for instance the definition of efficient and commonly-acceptable rules for maintaining and sustaining the (eco)system over long periods of time.