Gregory's Server
Example for a “single persona zone”: your job searching persona zone might include your LinkedIn, your GitHub, your personal website that has a resume in html and pdf, all accounts on job searching sites that you use for this job search, and the accounts on networking/event sites like Meetup where you rsvp for networking events.
Very naturally, any “single personal zone” should be really easy to use across sites. You already have decided to use a single personal for all of those, software might as well give you single-sign-in, and automatic attribute propagation across all sites in the zone. Example: if you change you move physical addresses during a job search, of course you want that address to automatically be updated across all sites in the zone.