Recommendation System Production-ready architecture for scalable recommendation systems with feature stores, multi-tier caching, A/B testing, and comprehensive monitoring. When to Use This Skill Load this skill when: - Building Recommendation APIs : Serving personalized recommendations at scale - Implementing Caching : Multi-tier caching for sub-millisecond latency - Running A/B Tests : Experimenting with recommendation algorithms - Monitoring Quality : Tracking CTR, conversion, diversity, coverage - Optimizing Performance : Reducing latency, increasing throughput - Feature Engineering : Mana…