Freestyle has really built with this in mind. We propose a primary architecture built around declarative configuration of the vm with a git repo as external source of truth.

If the VM crashes/you have another idea/you want to try something else it should be reconstructable from outside of the VM.

However, I think this is potentially unrealistic. While it is the ideal architecture, I hear more and more every day people who just want to have the VMs run for months at a time.