We have been using Figma (having our designers base all mockup design in it) for years and it’s going pretty well. We don’t take the Figma produced CSS for granted of course, but it’s indispensable in terms of analyzing what layout to use as well as having most of the styling ready as it is.

The designers don’t need to be frontend developers themselves but they must be familiar with the layouts in CSS (flex, grid) and the way LiveView’s two-tier frontend works. One thing we learned was that designers with mobile-only experience are not a good fit for web apps.

Figma is ok when designing reusable components with basic states (hover, focus, pressed (active)) and trying those out. Other than that it’s more of how you organize the files and mockups within them, but that’s always the case regardless of the tool.