Worked on the IPPL-framework/ippl repository to enhance the particle module by introducing comprehensive unit test coverage for its Gather/Scatter API. Focused on validating gather and scatter functionalities across multiple modes and policies, the work established a foundation for robust regression protection and improved maintainability. Leveraging C++, Kokkos, and MPI, the developer implemented GatherScatterTest.cpp to ensure correctness and facilitate integration into continuous integration pipelines. This approach improved test readiness and enabled safer, faster iteration on the particle module. The contribution laid essential groundwork for future verification efforts, supporting ongoing development and refactoring within a parallel computing environment using modern unit testing practices.