During February 2025, this developer contributed to the Xiangyu-Hu/SPHinXsys repository by refining the neighbor search feature to improve code maintainability and test reliability. They encapsulated the radius check within the NeighborBuilderContact component, replacing direct distance calculations with the kernel_->checkIfWithinCutOffRadius(displacement) method. This approach enhanced code clarity and encapsulation, reducing the risk of errors in future modifications. The developer also updated regression test data to align with the new logic, ensuring continued test coverage. Their work demonstrated solid C++ development and software engineering skills, focusing on robust feature refinement and maintaining the integrity of regression testing processes.