Realtime Attendance Sync

Presence utilizes Firebase Realtime Database and Firestore to ensure instant synchronization of attendance data and announcements across all connected users and devices.

How It Works

Presence is powered by Firebase, a backend-as-a-service platform that offers real-time capabilities. When any attendance event is created, scanned, or updated, the data is instantly reflected across all relevant user interfaces without requiring a manual refresh.

This functionality ensures admins can:

View live attendance status as users scan QR codes.
Monitor event activity as it happens.
Get instant visibility into newly added announcements or modifications.

Users benefit by:

Seeing real-time confirmation of attendance marking.
Receiving newly posted announcements immediately.

Firebase ensures data consistency, low latency, and fast delivery across global regions.

Technology Used

Firebase Firestore: Stores and syncs attendance records and event data in real time.
Firebase Realtime Database: Delivers lightweight, instant updates for announcements and presence detection.
Cloud Functions: Used to trigger background logic for processing updates, like updating attendance counts.

Admin Realtime Features

Live Dashboard View: Admins see the number of users who marked attendance per event in real time.
Realtime Announcement Propagation: When a new announcement is added, it's pushed to all users instantly.
User Activity Monitoring: Admins can check when a user scans attendance or opens an event.

User Realtime Experience

Instant Confirmation: Users see instant feedback once they scan the event QR code.
Live Announcements: Notifications for new announcements are pushed live without needing to reopen the app.

Performance Considerations

Presence uses Firebase's optimized delivery channels to maintain:

Low latency (under 200ms globally).
Automatic retry on unstable networks.
Offline sync for users with intermittent connectivity.

Firebase Plan Requirement

To maintain real-time features reliably, Presence recommends upgrading to Firebase Blaze Plan. This requires linking a credit card to your Firebase project. Note that Presence does not cover Firebase plan costs in its own pricing.

Security Notes

All real-time updates are authorized based on Firebase Auth roles.
Role-based access ensures only admins can view sensitive data.
Data is encrypted in transit and at rest.