Not using KGs for feature engineering/machine learning, but more for (personal) knowledge management. Using my own open source tool, Contextualise (https://contextualise.dev/ and https://github.com/brettkromkamp/contextualise). Check out the awesome-knowledge-management list for more KG and KM resources: https://github.com/brettkromkamp/awesome-knowledge-managemen...

At a professional level use KGs for educational web services in relation to curricula taxonomies.