Worked on the scikit-learn/scikit-learn repository to enhance the robustness of core validation utilities by addressing protocol handling in array operations. Focused on Python-based testing and data science workflows, the developer implemented a targeted test suite to ensure that the __array_function__ protocol is not triggered within the cross_validate and permutation_importance functions. This approach mitigated potential side effects from external array-like inputs, reducing the risk of silent failures in cross-validation and feature importance computations. By refining the testing strategy and improving protocol isolation, the work contributed to more reliable machine learning pipelines and strengthened the overall reliability of the codebase.