Worked on enhancing solver configurability in the gdtk-uq/gdtk repository by reinstating a configurable Flux Calculator option for the Newton-Krylov solver, previously available in Eilmer v4 and now ported to v5. This feature allows users to customize preconditioner formation, supporting more flexible solver tuning and experimentation. The work involved close collaboration across teams and required careful code migration and integration. Leveraging skills in algorithm development, numerical methods, and solver implementation, the developer used the D programming language to deliver a foundation for future performance optimizations, focusing on maintainability and extensibility within the solver’s architecture for ongoing research needs.