Is it a good idea to rely on the filesystem for a deployed webapp?

I'm developing a web application for the Cardano Blockchain, which currently has a very limited API and is not really developer-friendly.

All the operations required are done with a CLI (which has a wrapper in Javascript) and generates files with important data. My server currently relies on those generated files. It works well when testing with one computer, but at a medium scale (50 - 100k users /mo), will it scale horribly?

It's an express.js server in an EC2 instance together with a Cardano node (a piece of software running 24/7) and a database. It has autoscaling enabled.

I appreciate any comments/suggestions/answers