Aroarii Teheiura contributed to the govpf/openfisca-pf repository by first improving repository hygiene, updating the .gitignore to exclude IDE-specific files and maintain a clean codebase. In the following month, Aroarii developed a property tax penalty system, implementing fixed penalties and late payment interest calculations parameterized by declaration dates and prior tax amounts. This work involved extending the policy engine, introducing new parameters and variables, and updating test coverage to ensure accuracy. Using Python and YAML, Aroarii focused on backend development and tax calculation, delivering targeted features with careful attention to maintainability and policy validation, though without addressing bug fixes.