Worked on the Amsterdam/amsterdam-schema repository to address a data type inconsistency in the duur field across the natuurlijkePersonen and nietNatuurlijkePersonen schemas. Focused on schema definition using JSON, the developer identified and corrected a mismatch that previously affected validation reliability and data stability. By aligning both schemas to the correct duration type, the work reduced the risk of data drift and minimized downstream errors. The solution was delivered through a targeted commit with clear traceability, supporting ongoing efforts to harden the schema and improve data quality. This contribution emphasized careful attention to validation logic and robust schema maintenance practices.