Future Smart Cities will gather the Internet of Things, Big Data, and Cloud Computing to enable novel solutions to enhance citizens’ experience within the city. In opposition to traditional approaches based on vertical silos and ad hoc solutions, integrated middleware platforms can provide an unified infrastructure to support sophisticated, cross-domain smart city applications. Our research group has been developed a microservice-based open source smart city platform aiming at supporting collaborative, novel smart city research, development, and deployment initiatives. This platform provides high-level services to manage IoT resources, data storage and processing, and context-aware resource discovery. Preliminary experiments and our early experience indicates that the proposed microservice architecture supports important non-functional requirements, such as flexibility, evolvability and scalability. This sub-project aims to investigate the key challenges in smart city platform architectures, while evolving the existing platform prototype to support InterSCity researches and development. More specifically, we aim at integrating the microservice architecture with the scalable IoT communication and event processing middleware ContextNet to become the backbone for Big Data analytics and processing services; Data visualization services; City models; Integration of IoT devices; Integration with social networks; Application development support; Deployment in real environments in collaboration with the City of São Paulo government (Secretary of Innovation); and Simulation of real Smart City scenarios.