Purpose
Document the technical strategies used to ensure the platform functions reliably on low-bandwidth connections, including 2G and 3G networks.
Design Principles
- Target: Full functionality on 3G (1 Mbps); core functionality on 2G (50 Kbps)
- Page weight budget: Under 200 KB for initial load; under 50 KB for subsequent navigations
- Time to interactive: Under 3 seconds on 3G; under 8 seconds on 2G
Optimisation Strategies
Progressive Web App (PWA)
- Service worker caches core assets and career pathway content for offline access
- App shell architecture loads instantly, then hydrates with data
- Background sync queues actions (e.g., session booking) when offline and executes when connectivity returns
Asset Optimisation
- Images served via CDN with automatic compression and WebP conversion
- Lazy loading for below-the-fold images and non-critical resources
- Code splitting — only load JavaScript needed for current page
- CSS critical path extraction for fast first paint
Video Sessions
- Adaptive bitrate streaming — automatically adjusts quality based on connection speed
- Audio-only fallback when video bandwidth is insufficient
- Session content delivered as text summary if connection drops entirely
Alternative Access Methods
- WhatsApp Notifications — Session reminders and key updates via WhatsApp for users who prefer it
- SMS/OTP Login — Users without reliable email can authenticate via SMS one-time passwords
- USSD Access — Planned: basic mentor lookup and session scheduling via USSD menus for feature phones