No more DB, no more Auth system, no more backend code to create secure, privacy-first applications. You can be GDPR compliant without worrying about users’data and enjoy writing your apps instead of dealing with authentication and signups. At Userbase, we created an open-source SDK to manage users.
The really popular Daniel Vassallo @dvassallo and a small team of other developers created an open-source, scalable backend to host users information in a private and secure way. The whole API is just 12 endpoints and they can be called from a static page. The documentation is available at https://userbase.com/docs/quickstart/ while the code is on GitHub: https://github.com/encrypted-dev/userbase/
Creating a new app with Signup/Login and multiple DB per user is a matter of a few minutes. No server-side code needed, it is really serverless, JAMStack development.