Build a Multi-Tenant Database System Premium
Design a database architecture that isolates tenant data, prevents noisy-neighbor query interference, and allows individual tenants to be migrated, backed up, or throttled independently - all on shared infrastructure.
Build a Real-Time Multiplayer Game State Sync System Premium
Design a game state synchronization system that keeps all players in a match consistent with sub-100ms latency, handles lag compensation so fast-network players don't have an unfair advantage, and recovers gracefully when a player disconnects.
Build a Payment Processing System with Idempotency Guarantees Premium
Design a payment system that safely retries failed transactions without double-charging users, handles partial failures across payment provider integrations, and maintains a consistent ledger under concurrent requests.
Build a Push Notification Routing System Premium
Design a notification dispatch system that routes messages across APNs, FCM, and Web Push, guarantees at-least-once delivery with deduplication, and handles delivery failures with smart retry strategies.
Build a Secrets Management Vault Premium
Design a secrets store that encrypts credentials at rest and in transit, supports auto-rotation of API keys and DB passwords, and provides a full audit trail of every secret access.
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.