Caching
4 pieces of work and writing on this site touch caching.
Case studyPayment Hub — Two-Level CacheLocal JCS → Redis → databaseDecisionWhy a local cache in front of Redis, instead of Redis alone?Because the two layers answer different questions — one removes the network, the other removes the cold start.DecisionWhy Kafka for cache invalidation rather than Redis pub/sub?Ordering per key, replay for instances that were down, and an audit trail of what invalidated when.JournalDesigning a Two-Level Cache with JCS and RedisA local in-process cache in front of Redis buys latency and resilience. It bills you in invalidation. Here is the accounting.