* Fast builds are way more pleasant during development. "Incremental" per-article builds help, but not in all scenarios. Nothing kills my motivation faster than having to wait 30 seconds to preview a fix.
* Fast builds help us avoid jams in our automated push-live systems. Sometimes we have many editors updating pages during a big event. You could consider many different trade-offs when deciding how to manage these queues. But a fast build time erases a lot of those conversations.
We use 11ty on most of our sites. We've found 11ty itself to be fairly performant. The slugs tend to be everything related to processing assets: JavaScript bundles, Sass builds, image manipulation, etc. By streamlining those activities, we can usually get a site build down to just a few seconds.
That said, "instant build" is the dream that animates the best conversations on our team, and we've started building our own static site generator. Our SSG can run both on the server and in the browser. We want our editors in our CMS to be able to get instant, true previews of the page they're editing. Then we want to be able to push single-article builds live, instead of always rebuilding the whole site. It's early days yet. Maybe you'll see it on a "Show HN" some day.
