During April 2026, contributed to the informalsystems/quint repository by delivering a targeted bug fix that addressed the shadowing of default action names by state variables, such as --init and --step, which previously led to confusing error messages. The solution involved enhancing the toExpr() function with an expectedRole parameter, ensuring that these names resolve correctly to actions rather than state variables. This update improved simulator correctness and error clarity across both default and Rust backends. The work was implemented using TypeScript and full stack development skills, with updated integration tests to validate the new error reporting and validation logic.