During their work on the LLNL/serac repository, MacNider focused on enhancing both code clarity and extensibility in C++ physics modules. They addressed a documentation inconsistency by clarifying that material model functions return the first Piola stress, ensuring the API documentation accurately reflected the underlying object-oriented implementation. MacNider also introduced a virtual setParameter method in the base physics class, enabling derived modules to customize parameter behavior and laying the groundwork for future residual physics features. Their contributions combined C++ development, code refactoring, and documentation, resulting in improved onboarding, reduced risk of misuse, and a more flexible architecture for ongoing model experimentation.