Multiplayer Collaborative Canvas · View 06 of 23 · People and journeys
The decision this journey forces
- A client that edited for an hour offline comes back to a document that has moved on. Operations are rebased into the authoritative order under the same conflict rules as live editing — not applied as a block, and not discarded (ADR-12).
- Beyond the 30-day log horizon there is nothing left to rebase against, so the buffered work becomes a recoverable branch the user is told about. The one outcome the platform will not produce is a silent loss.
- This is the journey that makes a pure server-ordered model insufficient on its own, and the reason the reconnect path is a first-class flow rather than an error handler (view 14).
What it costs
- A local buffer of at least 10,000 operations on the client, and a merge path that can reject work it cannot reconcile without violating document invariants.
- Edits to an object someone else deleted are dropped and reported — the second visible conflict in the product, after the concurrent move.
Assumptions
- Reattach after a transient drop p95 ≤ 1.5 s including 30 s of catch-up.
- An offline session of 800 operations is typical for an hour of focused work.
