Worked on the Symbolics.jl repository, focusing on enhancing the correctness of symbolic differentiation in Julia. Developed and integrated new unit tests to verify that derivative calculations remain consistent whether functions are applied directly or through the BasicSymbolic representation. This approach strengthened the reliability and maintainability of the symbolic computation engine by expanding test coverage and introducing consistency checks, which help detect regressions earlier in the development cycle. The work centered on software development and unit testing, with an emphasis on foundational improvements rather than bug fixes, ensuring that future changes to the symbolic differentiation logic are robust and well-protected.