Back-up/failover instances for communities and users.

Every user and every admin of a community should be able to assign a failover instance in case the main instance goes down temporarily or permanently. All relevant data (posts, upvotes, settings, password hashes, mod log) would be permanently syched so you could just switch over in case of a downtime and most importantly, no content would be lost.

If you implement a feature to set the failover instance as your new main instance, that would also implicitly allow you to migrate users and communities elsewhere.

That works with Boost for Lemmy, so apparantly the data is already there in the backend (and at least one frontend).

Why do you think his whole neighborhood is on ketamines?