AWS Aurora, ElastiCache Patterns & DynamoDB — The Complete Data Layer

Part of my AWS learning journey — transitioning from Systems Engineer to Cloud/DevOps. This session completes the database picture — Aurora's read/write architecture, ElastiCache caching strategies, and DynamoDB from table creation to production-ready query patterns. 📋 Topics Covered # Topic Type 1 Aurora Endpoints — Writer vs Reader Concept + Interview 2 What Happens When the Aurora Writer Fails Concept + Cert 3 ElastiCache Caching Patterns — Lazy Loading, Write Through, Session Store Concept + Interview 4 Cache Invalidation Concept + Interview 5 DynamoDB — What It Is and When to Use It Concept + Interview 6 DynamoDB Table Creation — Keys and Settings Concept + Lab 7 Table Classes — Standard vs Standard-IA Concept + Cert 8 Capacity Modes — On-Demand vs Provisioned Concept + Cert 9 Warm Throughput Concept + Cert 10 DynamoDB Items & Attributes — CRUD Operations Concept + Lab 11 Query vs Scan — The Critical Difference Concept + Interview 12 Local Secondary Index (LSI) vs Global Secondary Index (GSI) Concept + Cert 13 Bonus Concepts — Streams, DAX, Consistency, Transactions Concept + Interview 14 Interview Questions Interview 15 Practice Tasks Practice Aurora Endpoints — Writer vs Reader Aurora doesn't give you just one database endpoint — it gives you two, each serving a different purpose and routing to different parts of the cluster. Writer Endpoint (Primary Endpoint): Always points to the current primary/writer instance. All write operations (INSERT, UPDATE, DELETE) go here. If a failover happens and a replica is promoted, Aurora automatically redirects this endpoint to the new writer — your application's configuration never needs to change. Reader Endpoint: A load-balanced endpoint that distributes read-only queries (SELECT) across all available Aurora Replicas. You don't manage which replica serves each query — Aurora handles the routing, spreading read traffic evenly across however many replicas exist. Why this architecture matters: In a typical application, read