During January 2026, Pfau enhanced the Newton-Raphson root finder in the google-deepmind/torax repository by introducing support for user-provided Jacobian functions. This feature was implemented in Python and focused on numerical methods and root finding, allowing users to override the default jacfwd behavior. By enabling custom Jacobian input, Pfau addressed the challenge of deriving Jacobians for complex problems, making the solver more adaptable and accurate across various domains. The work demonstrated a deep understanding of numerical algorithms and Python engineering, resulting in a more flexible root-finding workflow that broadens the applicability of torax for scientific and engineering users.