Build Amazon's Product Search Ranking Premium
Design a search ranking system that incorporates real-time inventory, pricing, and sales velocity signals into results, personalizes rankings per user, and re-indexes a product catalog of 500 million items.
Build Amazon's Review Aggregation Pipeline Premium
Design a review processing pipeline that deduplicates submissions, filters fraudulent reviews using behavioral signals, computes rolling star averages, and surfaces the most helpful reviews per product.
Build a Columnar Storage Engine with SSTable and Compaction Premium
Design a write-optimized storage engine that buffers writes in memory, flushes them to immutable SSTables on disk, and runs background compaction to merge files while keeping read amplification low.
Build Facebook Live Low-Latency Video Streaming Premium
Design a live video streaming infrastructure that ingests a broadcaster's stream, encodes it into multiple bitrates in real-time, and delivers it to millions of concurrent viewers with under 5 seconds of latency.
Build Facebook News Feed Ranking and Fanout Premium
Design a news feed system that generates a personalized ranked feed for 3 billion users, handles write fanout for posts with millions of followers, and serves the feed in under 500ms.
Build Faceted Search with Live Inventory Filters Premium
Design a search system that supports multi-dimensional filter combinations (brand, price, rating, availability) and reflects live inventory changes in filter counts within seconds of a product going out of stock.
Build a Geospatial Proximity Service Premium
Design a service that answers 'find all X within Y km of this location' in under 10ms at 500 million active entities, supports moving entities that update their location every few seconds.
Build Gmail's Spam Detection Pipeline Premium
Design a spam classification system that processes 300 billion emails per day, classifies each one in under 100ms before delivery, and continuously retrains models as spammers adapt their tactics.
Build Google Maps ETA Prediction Under Live Traffic Free
Design a route ETA system that incorporates real-time traffic signals from millions of moving devices, recalculates ETAs en route as conditions change, and serves predictions with under 200ms latency.
Build Google Photos Duplicate Detection Pipeline Premium
Design a pipeline that detects near-duplicate photos across 28 billion uploads per day using perceptual similarity rather than byte-level matching, and does so without storing a full copy of every image.