Database Architecture and Caching Questions

Explain design trade offs between relational and NoSQL stores and how to choose between managed relational databases and key value or document stores. Topics include data modeling, consistency and durability models, partitioning and sharding, indexing strategies, read scaling using read replicas, backup and recovery, multi availability zone failover, caching strategies with in memory stores, cache invalidation patterns, and operational considerations for scaling, monitoring, and cost management. Be prepared to discuss concrete architecture decisions and trade offs for specific workloads.