Application segmentation dissects the Smart City Information System Integration Services market according to the functional domains that consume integration capabilities. The primary application categories include Transportation, Public Safety, Utilities, Governance, and Healthcare. Transportation integration services enable real‑time traffic management, multimodal routing, and connected vehicle data aggregation, accounting for roughly 30 % of total market revenue. Public Safety, encompassing emergency response coordination, video analytics, and sensor‑based incident detection, contributes about 25 %. Utilities integration—covering smart grid, water distribution monitoring, and waste management—represents close to 20 % of the market. Governance applications, such as e‑government portals, citizen engagement platforms, and regulatory data exchange, generate approximately 15 % of the market. Healthcare integration, which links hospital information systems, telemedicine platforms, and public health monitoring, occupies the remaining 10 %. Moreover, the proportional weight of each application reflects regional policy priorities, with emerging economies allocating larger shares to Utilities and Transportation as they expand core infrastructure. This Smart City Information System Integration Services segmentation clarifies how each vertical drives demand for integration services and shapes the overall market size.