Live system notifications keep users informed about important events in real-time. Implement WebSocket connections for instant, bidirectional communication between server and clients. For simpler use cases, consider Server-Sent Events (SSE) which provide one-way communication from server to client.

Design notification systems with user preferences in mind. Allow users to choose notification types, channels (in-app, email, push), and frequency. Implement notification grouping to avoid overwhelming users with too many individual alerts. Provide clear action buttons within notifications when appropriate.

Ensure notifications are accessible with proper ARIA labels for screen readers. Test notification delivery across different devices and network conditions. Implement queuing systems for offline users with delivery upon reconnection. Monitor notification performance and user engagement metrics.