Tileuzhan Mukhamet focused on enhancing the robustness of periodic boundary conditions in the dealii/dealii repository, addressing a stability issue related to artificial cell face handling in distributed MPI runs. By refining the logic to skip artificial cell face degrees of freedom and prevent recursion on invalid cells, Tileuzhan improved both correctness and computational efficiency, particularly for the FE_RaviartThomas element. The work included adding a targeted MPI test to validate periodicity constraint creation, ensuring reliable behavior across parallel processes. This contribution demonstrated depth in C++, computational geometry, and finite element methods, with careful attention to testing and large-scale software reliability.