Not sure what you mean by backend does note signing?
Are you saying without using NIP-07 signer like nos2x or Alby?
Discussion
Yes, the use case being multiple people posting from an account where these users shouldn’t have access to the private key.
That's the usecase for nostr:npub1l2vyh47mk2p0qlsku7hg0vn29faehy9hy34ygaclpn66ukqp3afqutajft 's nsecbunker.
I don't know much about it but this article has details- https://habla.news/tony/nsecbunker