Most of the available solutions for creating digital twins force industry solution architects to resort to ad hoc implementations and models. These solutions lack reusability, scalability, and extensibility, which prevents the introduction of a human digital representation into existing twins, thus hindering the full shift to the new Industry 5.0 paradigm. The Human Digital Twin Core Infrastructure (Clawdite platform) is an extensible and flexible IIoT based platform with a dual benefit: On the one hand, it supports the creation of customised data representations of production systems and their entities, including humans; on the other hand, it provides a modular infrastructure with interchangeable components for easy instantiation and commissioning of digital twins. Clawdite's design is suitable for applications with different purposes and supports data flows with different volume, speed and variety.