When upgrading Drupal 7's blog module to a content type in Backdrop, all the blog content remained available in the database and live as nodes, however, the Title field is missing when creating new nodes.
My Drupal experience told me to first examine the content type configuration in the database, but several tables were missing. I found the tables I was expecting in the new JSON-based configuration files on the filesystem instead.
To see the JSON configuration, enable the new Configuration management module and list the node types under Development's Configuration Managment section. The specific file is
node.type.blog.json. The contents of my file was as follows: