Augmented Reality (AR) and more generally eXtended Reality (XR) appear as one of the most promising technologies for the next decades. XR applications based on these technologies require to localize themselves in the real environment in order to register 3D virtual content in relation to the real environment surrounding the user. To achieve this, XR systems use vision sensors coupled with a SLAM algorithm to estimate their pose (position and orientation) in real-time. Unfortunately, most of existing XR systems are limited to small environments and cannot address large scale experiences. To cope with this limitation, AR Cloud technology moves in the cloud spatial computing algorithms mainly consisting in localizing the AR device while locally mapping in 3D the real environment. This 3D map is then fused with a global map shared and updated by all AR devices in order to keep up-to-date a 3D knowledge of the real world mandatory for localizing AR devices. Taking advantage of 5G bandwidth and low latency, AR Cloud is a key technology to offer shared XR experiences anywhere, at any time in real environment changing over time. We present in this paper an AR Cloud platform experimented in industry environment for displaying maintenance guidance and instructions in AR to operators.