The CodeSnack IDE is a cloud-based IDE. All code compilation and execution happens in a Cloud Container.
Cloud Container is powered by Linux (Ubuntu 20.04). All the data that you have in your home (/home/user) folder is persistent, but everything outside a home folder is not and reset to the default state once the container terminates.
The Cloud Container terminates after 10 minutes of inactivity in the app. When your return to the app, the Cloud Container will be started again.