The idea of intelligent cloud services is introduced and the stages of their design and development are characterized. A cloud platform supporting implementation and testing of such services is outlined and its generic architecture is given. An original model for their quality assessment is also proposed. Its metrics enable developers to monitor the quality assurance progress at every stage of the service development process and make it more resilient and robust to the various types of issues encountered during this process. As a case study, interesting relationship between achieved values of quality metrics of intelligent services and the technical readiness levels of the proposed platform have been identified.