Worked on the tc39/ecma262 repository to implement Import Attributes support for JavaScript modules, delivering a core feature that enables declarative module loading. The approach involved updating the ECMAScript grammar to allow optional 'with' clauses in import and export declarations, as well as adjusting both static and runtime semantics to handle attribute information during module requests and loading. This work required a deep understanding of language design and module systems, ensuring the standard aligns with evolving module loading semantics. The changes set a foundation for interoperable tooling and runtime optimizations, reflecting careful attention to ECMAScript specification details and JavaScript language evolution.