Zhiqing Rui contributed to the llvm/circt repository by implementing robust SystemVerilog union type handling in the MooreToCore pass, addressing stability and error diagnostics for hardware type conversions. Using C++ and MLIR, Zhiqing expanded the type system to prevent crashes when processing union types and introduced explicit error messages for unsupported module port types, improving downstream usability for CIRCT backends. Additionally, Zhiqing enhanced documentation reliability by correcting a CMake build example in the README, ensuring accurate onboarding for new contributors. The work demonstrated depth in compiler design, error handling, and hardware design, focusing on practical improvements to developer experience and tool stability.