During their tenure, Darice Guittet enhanced geothermal cost modeling in the NREL/SAM and NREL/ssc repositories, delivering new equations and API functions for more accurate cost estimation and streamlined O&M calculations. Working primarily in C++ and CMake, Darice improved build system reliability and documentation, reducing integration risk and supporting future development. In NREL/ssc, Darice addressed a numerical stability issue in battery modeling by introducing an absolute value threshold, preventing division by near-zero values and improving simulation robustness. The work demonstrated depth in software engineering, with careful attention to maintainability, traceability, and data consistency across complex scientific codebases.