Multi-platform Design System at Booking.com

Booking.com has 1 design system to rule them all.

Their key challenges included: issues with scalability of color palette and dark mode, border-radius support, typography limitation and viewport, themeing support and tooling, foundation implementation, duplicated component libraries in figma

They have talked about how they conducted design assessment of the current affairs, defining detailed specs, working closely with developers in order to obtain inputs related to technical feasibility, syncing Figma properties with code properties

They have BUI themer plugin

https://www.figma.com/community/file/1105910527004188461
https://www.figma.com/community/file/1101534616529110700