In the recent decade, the concept of Smart Tourism Destination (STD) has emerged to represent both a strategic aim to develop sustainable competitive advantages for tourism destinations or wider regions, and a managerial approach and dimensions to enhance data-driven development to measure and apply smart technologies for competitive and inclusive change in a tourism ecosystem. In tourism destination development globally, the aim for sustainable digital transformation in low-productivity business sectors is one of the key drivers for smart tourism and smart destination development. More recently, the global Covid-19 pandemic has given a boost to touchless, digital and green tourism development initiatives in the EU and worldwide. To advance sustainable digital transformation with agile methods in STD development, a systemic service platform approach and agile prototyping with smart emerging technologies, (eg. with AI, IoT, Augmented & Virtual Reality, 5G and Robotics), and multi-stakeholder co-creation is needed to engage key tourism industry ecosystem representatives. This conceptual paper advocates that open-source solutions combined with comprehensive multi-stakeholder co-creation aid in prototyping a systemic digital platform solution for smart tourism destinations. The paper concludes with an illustration of a conceptual model of service platform development for smart destinations, utilizing network co-creation with quadruple-helix stakeholders for sustainable regional impacts.