Build a Distributed Lock Manager and Leader Election Service Premium
Design a distributed coordination service that provides mutual exclusion across a cluster, implements lease-based locks that expire on node failure, and enables leader election for singleton workloads.
Build a Distributed Session Store for 50M Active Sessions Premium
Design a session storage system that maintains 50 million active sessions with sliding expiry, serves session data in under 5ms, and handles node failure without logging users out.
Build a Distributed Unique ID Generator Free
Design a system that generates globally unique, roughly time-sortable IDs across thousands of nodes with no coordination overhead and zero collisions under any failure scenario.
Build a Distributed Write-Ahead Log Premium
Design a durable WAL that survives single-node crashes, replicates log entries across nodes before acknowledging writes, and supports point-in-time recovery by replaying from any checkpoint.
Build a DRM Token Vending System for Premium Video Premium
Design a digital rights management system that issues short-lived playback licenses to authenticated subscribers, prevents license sharing across accounts, and revokes access instantly when a subscription lapses.
Build an Enterprise SSO System Federating 500 SaaS Applications Premium
Design a Single Sign-On platform that federates identity across 500 SaaS applications using SAML and OIDC, enforces MFA policies, and propagates user deprovisioning to all connected apps within seconds of an account being disabled.
Build an Event Sourcing and CQRS Audit Trail Premium
Design an event-sourced system where every state change is stored as an immutable event, supports replaying 3 years of history to reconstruct any past state, and separates read and write models for query performance.
Build a Feature Flag Service Free
Design a feature flag platform that rolls out changes to a targeted percentage of users with zero downtime, supports instant kill switches, and propagates flag changes globally in under 500ms.
Build a Flash Sale System for 500K Concurrent Checkouts Premium
Design an e-commerce checkout system that handles a sudden rush of 500,000 concurrent purchases without overselling a limited inventory, and ensures every confirmed order is fulfilled.
Build Google Docs Real-Time Collaborative Editing Premium
Design a collaborative document editor where multiple users can type simultaneously, see each other's cursors in real-time, and never lose edits even when two users modify the same paragraph at the same time.