Build a Self-Healing Service Mesh Premium
Design a service mesh that continuously monitors the health of every service instance, automatically reroutes traffic away from degraded nodes, and triggers remediation actions without human intervention.
Build a Shadow Traffic / Dark Launch System Premium
Design a traffic mirroring system that duplicates live production requests to a canary service in real-time, compares responses for divergence, and generates a confidence report without any user-visible impact.
Build a WebSocket-Based Presence System Premium
Design an online presence and typing indicator system that tracks 10 million concurrent users, propagates status changes to relevant subscribers in under 200ms, and handles connection drops gracefully.
Build WhatsApp Message Delivery with Offline Queuing Premium
Design an end-to-end encrypted messaging system that delivers messages to online users in under 100ms, queues messages durably for offline users, and guarantees delivery exactly once when they reconnect.