The internet of things (IoT) is one of the most disrupting revolutions that is characterizing the technology ecosystem. In the near future, the IoT will have a significant impact on people's lives and on the design and developments of new paradigms and architectures coping with a completely new set of challenges and service categories. The IoT can be described as an ecosystem where a massive number of constrained devices (denoted as smart objects) will be deployed and connected to cooperate for multiple purposes, such a data collection, actuation, and interaction with people. In order to meet the specific requirements, IoT services may be deployed leveraging a hybrid architecture that will involve services deployed on the edge and the cloud. In this context, one of the challenges is to create an infrastructure of objects and microservices operating between both the edge and in the cloud that can be easily updated and extended with new features and functionalities without the need of updating or re-deploying smart objects. This work introduces a new concept for extending smart objects' support for cloud services, denoted as a sidecar object. A sidecar object serves the purpose of being deployed as additional component of a preexisting object without interfering with the mechanisms and behaviors that have already been implemented. In particular, the sidecar object implementation developed in this work focuses on the communication with existing IoT cloud services (namely, AWS IoT and Google Cloud IoT) to provide a transparent and seamless synchronization of data, states, and commands between the object on the edge and the cloud. The proposed sidecar object implementation has been extensively evaluated through a detailed set of tests, in order to analyze the performances and behaviors in real- world scenarios
