We’ve had the new editor, Gutenberg, for a while now, but some plugins have been slow to update their post interfaces. While this still works, it could be a much better experience if we embraced the new editor pattern, but not everything works as a block. Sometimes you need to customize the sidebar panel, or create a new sidebar. This talk will take you through the steps of updating an existing metabox to a sidebar panel, and cover some other, more advanced examples so you can apply this to your work.