NoSQL Databases Production-grade NoSQL database patterns with MongoDB, Redis, Cassandra, and DynamoDB. Quick Start Core Concepts 1. Redis for Caching & Real-time 2. DynamoDB Patterns 3. Cassandra for Time Series Tools & Technologies | Tool | Purpose | Version (2025) | |------|---------|----------------| | MongoDB | Document store | 7.0+ | | Redis | Cache, pub/sub | 7.2+ | | Cassandra | Time series, wide column | 5.0+ | | DynamoDB | Managed key-value | Latest | | Elasticsearch | Search, analytics | 8.12+ | | ScyllaDB | High-perf Cassandra | 5.4+ | Troubleshooting Guide | Issue | Symptoms | Roo…