Worked on the antmicro/verilator repository to enhance simulation robustness by addressing a critical null pointer dereference issue in class member trigger expressions. Applied C++ development and debugging skills to implement a detection mechanism for class member access patterns, wrapping sensitive statements and expressions with null checks. This approach prevented dereferencing null pointers in sensitivity expressions, reducing crash risk in complex simulation models. The solution was delivered with minimal impact on performance and existing code paths, demonstrating a focus on defensive programming and long-term maintainability. Python scripting and software testing were also utilized to ensure the reliability and safety of the fix.