During this process, IA and user flow shortcomings were identified in the features and sites being redesigned and improvements were made to address these.
The resultant design system includes both light and dark modes (using a simple palette switch) and is designed with accessibility (WCAG) in mind. The design system is also fully responsive.
As part of the deliverables, I documented the individual components for the developers, including content data models. There are options and in some cases multiple states associated with each component.