Niels Pardon upgraded the Gradle build configuration for the substrait-io/substrait-java repository, focusing on improving API exposure and dependency management. By transitioning the core and isthmus modules from the java plugin to java-library, Niels ensured that API dependencies such as protobuf-java and internal dependencies were explicitly defined and correctly exposed. This approach clarified the module dependency graph, reduced the risk of transitive dependency issues for downstream consumers, and enhanced overall build maintainability. The work demonstrated a strong grasp of build system configuration and dependency management using Gradle and Kotlin, addressing a nuanced aspect of project reliability and developer experience.