We present a declarative solution to determine, in a data-aware manner, application service placements and SDN data routings over Cloud-IoT infrastructures while meeting functional (software, hardware, IoT) and non-functional (security, latency, bandwidth) application requirements. The solution employs continuous reasoning to speed up the reconfiguration of application placements and routing decisions at runtime, when needed. An open-source Prolog prototype is presented and assessed over a scenario based on lifelike data.