Collaboration
Real-time collaboration
Several people in one design at once — how edits merge, what presence shows, and what happens when two people touch the same thing.
More than one person can be in the same design at the same time. Edits are merged rather than queued, so nobody has to wait for a lock and nobody's work overwrites anybody else's.
Presence
You can see who else is in the design and where they are working. Presence is per-person: two browser tabs signed in as the same account are one person, and will not show as two.
Note
That is worth knowing when you are testing something — you cannot check collaboration behaviour by opening a second tab as yourself. It needs a second account.
When two people edit the same element
Concurrent edits to *different* things simply merge. Concurrent edits to the *same* element are detected and surfaced, so the two of you can settle it — rather than one edit silently winning and the other disappearing.
Connection loss
If your connection drops, the editor keeps working locally and re-synchronises when it comes back. A brief disconnection is not a reason to stop drawing.
After a long disconnection, reload
If you have been offline for a long stretch, or the editor tells you the session has ended, reload the page rather than continuing. That guarantees you are working against the current state rather than a stale local copy.
Restores are global
Restoring a version changes the design for everyone currently in it. Say so before you do it.