If you need an instant Backend (database + api builder) but also a CMS in the cloud you can check our combo:

Cloud Backend: https://cloudbackend.appdrag.com and Cloud CMS: https://appdrag.com

It's a fully serverless solution, nothing to install on your side, you can do everything in the browser directly. and we have a free tier :)

Also we have no lock-in, you can export everything in a ZIP, static files, db backup in mysql format, API source code in your language (Node.js, Python, Java, C#, Go, ...)