The development of smart cities has evolved through several generations since the beginning. Many requirements and technologies have been devised to facilitate the implementation of the smart city concept, among which the smart city platform stands out. The implementation of smart city platforms facilitates the advancement of technology-driven services in smart cities, hence enhancing the overall wellbeing of their residents. Nevertheless, the existing notion of smart cities has evolved into a more comprehensive model encompassing intelligence, sustainability, and resilience. The paradigm shift in urban development necessitates fulfilling diverse needs by both smart cities and platforms. Research about the current smart city platforms necessitates adaptation to align with the criteria for developing smart, sustainable, and resilient cities. This study presents the Cognitive City Platform as a digital public infrastructure compatible with advancing intelligent, sustainable, and resilient urban areas. The adaptability of the system architecture on the cognitive city platform allows for its implementation in cities of different scales and sizes. Additionally, the platform incorporates city anomaly analytics as its initial level of cognitive functionality. This study additionally presents findings regarding the practical usage of the Cognitive City platform and empirical data about assessing its performance and scalability.