One of my first launches when I joined Shopify was adding new features to automatic discounts. A limited version of this product had already gone live but our merchants needed more capabilities so they could set a percentage off or set amount on all their products.
The UX writing ensures merchants understand that this type of discount can't be used at the same time as discount codes and where it appears in their customer's buying journey. I also improved the description of both codes and automatic discounts to ensure merchants understood upfront which discount best fit their needs.
Since launch, this feature has been widely used particularly during busy sales periods such as black Friday and cyber Monday.