Every production AI agent eventually hits the same wall. After a few sessions, it starts forgetting things it was told, re-asking questions already answered, and pulling context that is months stale. The problem is rarely the model. It is the memory layer.
Picking a memory architecture is one of the first decisions that separates prototype agents from systems that hold up under real workloads. Short-term session state, long-term episodic memory, semantic retrieval, and procedural context all behave differently, degrade differently, and require different infrastructure. A vector database that works fine for a single-tenant demo can fall apart when thousands of concurrent agents start reading and writing to the same index. A Redis cache that handles conversation buffers beautifully offers nothing when an agent needs to retrieve context from six weeks ago.
