Build a Social Media Hashtag Trending System by Region Premium
Design a system that indexes every post's hashtags, computes trending tags per geographic region updated every minute, and surfaces breakout trends that are gaining velocity even before reaching high absolute volume.
Build a HIPAA-Compliant Tamper-Evident Audit Log Premium
Design an audit logging system for healthcare data where every record access and modification is logged immutably, the log itself cannot be altered without detection, and auditors can query it efficiently.
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 a Medical Record Deduplication System Premium
Design a patient identity matching system that detects and merges duplicate patient records across hospital systems using probabilistic matching, handles conflicting data fields in the merge, and provides a full audit trail of merges.
Build a Model Versioning and A/B Testing System for ML Premium
Design a model deployment system that safely rolls out new ML models alongside existing ones using traffic splitting, measures business metrics per model variant, and automatically rolls back when a new model underperforms.
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 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.
Build a QR Code Generation and Analytics Service Free
Design a system that generates dynamic QR codes at scale, tracks every scan with device and location metadata, and lets users update the destination URL without regenerating the QR code.