Two lines of work were allowed to diverge — a branch, a draft, an offline stretch — and both changed the same thing. Merging silently would discard one intent without anyone deciding; refusing to merge stops the work. Reconciliation makes the collision a first-class object: both versions shown, comparable, with reintegration blocked until a person picks and the choice recorded.
The pattern is as much about placement as mechanism. Live co-editing surfaces never show conflicts — concurrent edits are absorbed silently, and the industry has spent a decade retiring even paragraph locks in favour of silent merge. The reconciliation surface belongs exactly where divergence was deliberate: the offline return, the branch merge, the pull request. There it blocks: the merge button deactivates, the branch review lists each collision side by side, and a person picks.
The documented failure is surfacing without support: a conflicted copy dropped beside the original, with no way to compare the versions — the collision preserved but the deciding made impossible.
Consequences
- the collision is a first-class object: both versions visible and comparable, the choice recorded — never a conflicted copy dropped beside the original with no way to compare
- the surface exists only at the return of deliberate divergence: a live ground merges concurrent edits silently, and a collision surfacing mid-flow says the boundary was drawn wrong, not that this surface is missing
- what the mechanism can show separately is what a person can pick separately: reconciliation's grain is set by the parting's grain
Resources & references
- Kleppmann, Wiggins, van Hardenberg & McGranaghan (2019) Local-first software — the same-property residue a merge cannot resolve, and the Evernote conflicted-copy failure
- Semantic conflict model for collaborative data structures — implicit CRDT resolution as “opaque to users”; the case for explicit, visible conflicts
- GitHub Docs: About merge conflicts; Figma Learn: branch conflict review
- Burghardt (2009) Working Through Screens, B7 “Object ownership and availability rules” — the locking era’s form of the same legibility claim
Appears in
Working on the same thing
- Working apart and returning, step 3 — Resolve conflicting changes
Related patterns
Complements
- Draft and publish — the parting whose return reconciliation guards
- Comparing — showing the colliding versions is comparing's version case put to work
Related to
- Undo — the version not picked is a removal; undo is its recovery