Worked on foundational improvements to the Wagenpark feature within the Amsterdam/amsterdam-schema repository, focusing on schema definition using JSON. Delivered a dataset versioning framework and updated service contracts schema to enhance governance and traceability for Wagenpark-driven workflows. The technical approach involved repositioning a key schema attribute to facilitate future migrations and contract validation, ensuring backward compatibility and smoother integration. By establishing clear versioning and contract structures, the work laid the groundwork for downstream integrations and service contract enforcement. This initial schema modification supports maintainable evolution of the dataset and provides a robust foundation for future Wagenpark feature development and validation.