Gatsby Themes - Ship and use chunks of Gatsby functionality as npm packages
Using a Gatsby theme, all of your default configuration is abstracted out of your site, and into an installable package. You can seamlessly update a theme, compose themes together, and even swap out one compatible theme for another.
Incremental Builds in Gatsby Cloud - From static sites to real-time builds
With Incremental Builds in Gatsby Cloud, when a developer or content creator makes a data change in their CMS, Incremental Builds will rebuild only what’s necessary—giving you up to 1000x faster builds with most data changes happening in under 10 seconds!