Build a Last-Mile Delivery Tracking System Premium
Design a delivery tracking system that ingests GPS pings from thousands of drivers every few seconds, recalculates ETAs dynamically as conditions change, and streams live location updates to customers without polling.
Build a Live Poll and Real-Time Vote Tally System Premium
Design a polling system that handles 1 million concurrent votes during a live broadcast, shows results updating in real-time for all viewers, and prevents ballot stuffing without requiring user accounts.
Build a Live Leaderboard for a 10M-Player Tournament Premium
Design a real-time leaderboard that updates rankings as scores change during an active tournament with 10 million concurrent players, serves the top-100 rankings in under 10ms, and shows each player their own rank instantly.
Build Meta's Notification Delivery System Premium
Design a notification platform that routes alerts across push, in-app, SMS, and email channels, handles traffic spikes of 10x during viral events, and respects per-user notification preferences in real-time.
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 Netflix Adaptive Bitrate Streaming Engine Free
Design the client-side ABR algorithm and server-side infrastructure that switches video quality in real-time based on available bandwidth, minimizing rebuffering while maximizing perceived quality.
Build Netflix's Recommendation Engine Premium
Design a personalization engine that generates a unique homepage for 280 million users, blends collaborative filtering with content-based signals, and updates recommendations within hours of new viewing behavior.
Build a Personalized Typeahead Search Engine Premium
Design a search suggestion system where the same prefix returns different top results per user based on their history, while still surfacing globally trending queries and completing within 50ms end-to-end.
Build Pinterest's Image Deduplication System Premium
Design an image deduplication system that identifies near-duplicate and visually similar images across 300 billion pins using perceptual hashing, deduplicates at ingest time, and reclaims storage for matched duplicates.
Build a Podcast Transcription and Chapter Detection Pipeline Premium
Design a pipeline that transcribes uploaded audio in near real-time, identifies natural topic boundaries to auto-generate chapter markers, and makes the full transcript searchable within minutes of upload.