This is a plugin from the folks that make GeneratePress, my go to theme for WordPress projects.
This plugin approaches Gutenberg blocks the way GeneratePress approaches themes, which is to build smaller components that are reusable and build on each other. Combined with the so-called GeneratePress feature “Elements”, which allows one to inject arbitrary content and/or code into various places in the theme, well, I’ve got a complete layout engine here working the way I do: bits of reusable code building on each other.
Check out the GP hooks diagram (and note this is the $50 premium plugin feature, a great deal because I didn’t have to write it):
There are others at Hooks Visual Guide - Documentation.