Brain Uploading: Pervasive and universal, just about.  The Eldrae, after all, being naturally unaging, find the notion of accidental death rather unpleasant, and so took to this technological advancement with enthusiasm; and, as rabid technophiles, even more so once the other technologies it enables – reinstantiation, mindcasting, forking, gnostic overlays, etc. (unlike a lot of universes, there are no convenient laws preventing you from screwing around with mind-states in all the ways you might expect to be able to) – came along; and now are enthusiastically selling immortality to the entire rest of the Galaxy, or at least everyone they can reach.  (And, incidentally, considering governments that ban this sort of thing as, essentially, being morally, if not legally, guilty of the mass murder of everyone who dies in their jurisdiction and would have preferred not to; immortalists vs. ephemeralists is a major galactopolitical issue.)

To the point, in fact, that modern – and thus highly engineered – brains come with the technology (“noetic architecture”) for minds to hop in and out designed right in.

Also, this is how you reach the afterlife (see Deus Est Machina).