Seriously? I believe you, but if it's taking hours then it seems like the problem isn't as much with SASS but rather the way they write CSS or their build process. If they only recompiled changed files, there's no way it could take "hours".
Even if they recompile everything... all CSS needs to be interpreted by the browser at some point. How much CSS do they have?
That being said, what are the speed comparisons like?
Yeah, I'd love to hear more from Hampton on the hours thing. What actually takes so long? Why does the number of developers matter? I've worked on some substantial (though not LinkedIn-sized) projects that used SASS and I've never clear seconds in compilation time.
They use https://github.com/linkedin/archetype which is an extension on top of Compass. Including all those libraries can mean a TON of memory and processing is required. Mixins calling mixins calling mixins. Plus, custom ruby extensions, etc. The needs of organizing hundreds of developers logically and making sure the code is optimized can be a hauss.
Even if they recompile everything... all CSS needs to be interpreted by the browser at some point. How much CSS do they have?
That being said, what are the speed comparisons like?