Slack Code moves AI coding agents from individual terminals into shared Slack channels where teams can see diffs, previews, and plans in real time. But it solves management's visibility anxiety, not engineers' productivity bottleneck — the real battle is over who becomes the agent control plane.
Liveblocks packages rooms, presence, conflict-free storage, comments, and notifications as managed product primitives; adoption still requires alignment with existing auth, canonical databases, and data lifecycle.
PartyKit concentrates WebSocket coordination in room-keyed stateful servers for multiplayer and presence, while durable documents, authorization, hibernation, and platform ownership still need explicit design.
Yjs uses shared types and commutative, associative, idempotent binary updates to converge concurrent edits; it does not prescribe transport or include authorization, persistence, or domain conflict resolution.