Worked on enhancing the ResizeObserver callback context in the w3c/csswg-drafts repository by updating the callback to pass the observer as a second argument and preserving the callback’s context. This change improved the ergonomics of the ResizeObserver API, enabling developers to implement more robust resize logic and facilitating better debugging. The approach focused on standards-driven development, aligning the implementation closely with CSSWG draft expectations. JavaScript and DOM APIs were used to deliver this targeted feature, with clear, maintainable commits and a well-defined scope. No major bugs were addressed during this period, emphasizing a focused contribution to front end development.