The Trade-Off Between Design and Development

There's a lot of talk about building and testing o shared things in isolation, as opposed to always doing them in the context of a particular page or something like that. What do you all think are the trade offs betweeny starting with a, doing it sort of gide first, or verses, doing it in a page first and then extracting it later? We have definitely gone both ways at times. A style guide index, i thinks, be primarily for the things that are used across the siht and that we know will re use across the site.