This was linked in our 5.0 release post, but as a reminder, the WordPress 5.0 Field Guide was published right before the launch last week. It’s an excellent summary of all the changes and new enhancements for theme and plugin developers to digest.
There are quite a few, so if you haven’t yet added this to your reading list, you probably should. I found the information on the REST API in WordPress 5.0 especially interesting.
