I’ve been experimenting with services such as Contentful, Prismic, and finally Sanity. Currently, each post on this site is a Markdown file, and it is converted into a HTML page by 11ty when the site is built. The “content-as-a-service” platforms return data over the wire, and each record in the GraphQL response is turned into the post it represents.
However, I think I prefer to keep each post as a file, all wrapped up on Github, so it’s back to Netlify CMS for me.