Looking for a secure framework which can store and load your system configurations and applications to an initramfs from an external drive upon startup? Give Invelinux a shot!
Linux distribution which stands for "Initramfs Volatile-storage based Embeddable Linux" is an operating system that combines volatile and non-volatile storage by running the base system on RAM and storing system settings and applications on an external drive, this approach makes the system faster and also prevents unsaved data from getting wiped since data is saved on your external drive with the AMPS framework.
Invelinux is a project aiming to teach people intermediate linux knowledge. Even with its minimal architecture which you can learn more about here, it is an exceptional tool to learn more about how OS development is done in the backend. Even if you hate it, you'll still probably learn something.
Checking the Invelinux wiki is your best bet and is highly recommended. If you didn't check the wiki, now is the best time to check it otherwise you might skip crucial steps or get lost during installation.
Linux(R) is the registered trademark of Linus Torvalds in the U.S. and other countries.