E5-F2: Real-Time Position Updates

Epic: E5: Waiting Queue System

Size: M (Medium)

Problem / Outcome

Users see their queue position updating in real-time.

Scope

In-Scope:

• Client countdown (decrement every second)
• Server sync every 60 seconds
• WebSocket or Firebase channel for updates

Out-of-Scope:

• SMS updates

Acceptance Criteria

• AC1: Client decrements position locally every second for smooth UX
• AC2: Server syncs actual position every 60 seconds
• AC3: Position updates received via WebSocket/Firebase while app is open

Data Model Impact

No new tables required.

Real-time channel:
- Firebase topic: queue/{match_id}/{user_id}
- or WebSocket: /ws/queue/{match_id}

Message format:
{
  "position": INTEGER,
  "estimated_wait_minutes": INTEGER,
  "queue_size": INTEGER,
  "sync_at": TIMESTAMP
}

Permissions/Roles

• Authenticated user in queue

How to Verify

npm test -- --grep "position updates"

Expected: Position updates flow correctly, sync corrects drift.

Dependencies

• E5-F1: Queue Join and Position Assignment

Implementation Tasks

See E5: Waiting Queue Tasks

Doc References

• Waiting Queue Flow

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Last Updated: January 2026