During October 2025, Jyri-Matti Lähteenmäki focused on backend development for the geotools/geotools repository, addressing a critical issue in GeoJSON parsing. He delivered a targeted bug fix that ensures null values in FeatureCollection properties are correctly parsed as null, rather than defaulting to primitive values, which previously caused exceptions when arrays contained nulls. This change improved the robustness and data integrity of the GeoJSONReader, reducing runtime errors for downstream geospatial data processing. Jyri-Matti applied his expertise in Java, JSON parsing, and unit testing to implement a lean, maintainable solution, demonstrating depth in backend engineering and careful attention to data handling.