Yup! That's the avenue we took. A React app as an editor, content blocks are represented as a large JSON structure. That structure is stored in a DB via Drupal. (The editor is actually jacked into the Drupal page editor). We use GraphQL as our integration service. There's a shared "blocks" library so the editor can do the layout, store the JSON and the front-end website can interpret that JSON and use the same library to rebuild the component structure. I will say that it's a neat system. Some folks are VERY attached to it. I don't feel it fits the business needs so I'm investigating other options.

Best of luck on your CMS! I'm always intrigued by what others build - so please don't take my experience as any sort of criticism - I'd love to see your project succeed!