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 Change Data Capture Pipeline Premium
Design a CDC pipeline that streams every database write to downstream consumers in the order they occurred, preserves transactional boundaries, and guarantees no event is dropped even if a consumer is temporarily offline.
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 a Content Moderation Pipeline Premium
Design a content moderation system that uses ML classifiers to automatically detect policy violations in text, images, and video, routes borderline cases to human reviewers, and minimizes both over-removal and under-removal.
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 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.
Build Instagram Explore Real-Time Recommendation Engine Premium
Design a content discovery system that generates a personalized Explore grid for 2 billion users, refreshes recommendations as users scroll, and surfaces trending content within minutes of it going viral.
Build Instagram Stories Expiry and Archival Pipeline Free
Design a system that automatically expires 500 million Stories after 24 hours, moves them to cold archival storage, and lets users retrieve archived Stories on demand without impacting live traffic.
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.