CloudStream service is a Full Management Service in Huawei Cloud. Support several features, such as On-Demand Billing, easy-to-use Stream SQL in online SQL editor, test Stream SQL in real-time style, Multi-tenant, security isolation and so on. We choose Apache Flink as streaming compute platform. Inside of CloudStream Cluster, Flink job can run on Yarn, Mesos, Kubernetes. We also have extended Apache Flink to meet IoT scenario needs. There are specialized tests on Flink reliability with college cooperation. Finally continuously improve the infrastructure around CS including open source projects and cloud services. CloudStream is different with any other real-time analysis cloud service. The development process can also be shared at architecture and principles.