In collaboration with Inbex d.o.o., a comprehensive XR platform was developed based on a realistic digital twin of the assembly line. It features high-fidelity models of key workstations, tools, products, and interactions. The system enables spatial training via HoloLens and other XR devices, allowing users to perform everyday assembly tasks in an immersive, guided environment. Special attention was given to scalability and multi-device support to ensure long-term system sustainability.