Having the opportunity to build a Design System from scratch meant that accessibility became part of the process, rather than an afterthought. 

Some of the key principles taken into account were: checking colour contrast on different background and across different interaction states (this included me going down a deep rabbit hole of accessibility standards for disabled buttons) 

including text labels with icons on mobile navigation

consistency across layouts and similar UI elements

that adherence to accessibility standards is a shared mission. 

The Design System played a key role in ensuring a successful launch:

it provided a cohesive look and feel for the rebrand

it streamlined the design process,

it led to a faster design to market time, providing developers with a single source of truth and a set of reusable components and patterns