Worked on the web-infra-dev/rspack repository, focusing on enhancing type safety within the LazyCompilationOptions test callback. Refactored the codebase by updating the module parameter’s type from any to Module, which improved compile-time checks and provided better autocompletion support in modern IDEs. This change streamlined the developer experience and contributed to more reliable builds by catching type errors earlier in the development process. The work was implemented using TypeScript and involved advanced code refactoring and type definition skills. No major bugs were addressed during this period, with efforts concentrated on improving maintainability and tooling for future development.