Dynamic Funds had multiple product teams all building slightly different versions of the same buttons, forms, and layouts. I led the design system that fixed that.
The work was less "make it pretty" and more forensic — auditing what already existed, finding the patterns worth keeping, and building a component library and documentation that developers could actually implement without guessing.
Once it shipped, new features stopped needing a design review just to get the basics right — type, color, spacing were already decided. That's the actual win: less time re-litigating fonts, more time on the parts of the product that needed real thinking.