> The twelve-factor methodology can be applied to apps written in any programming language, and which use any combination of backing services (database, queue, memory cache, etc).
Not every landscape fits the WEB-LOGIC-mumble_db_mumble model. Sometimes your backing services are not Someone Else's Problem: maybe you need to curate them and deploy them with the rest of your 12F fleet (applying 12F where possible) but the realities are lots of handholdy things like state, schemas, migrations, and entropy in general.