During August 2025, Kosb15 enhanced test reliability and static analysis in Java projects by contributing to the junit-team/junit5 and uber/NullAway repositories. In junit5, Kosb15 implemented validation logic to ensure Suite Display Names are not blank, emitting warnings to prevent misconfigured test suites and improve maintainability. For NullAway, Kosb15 refined the static analysis process by suppressing unnecessary CastToNonNull warnings for return values from @NullUnmarked methods, reducing false positives during incremental null-safety migrations. These changes, developed with Java and annotation processing, expanded test coverage and strengthened the robustness of null-safety tooling, directly supporting safer code evolution.