RAG brings books to the exam. Knowledge Engineering teaches Agents to study. Memory architecture matters more than retrieval tuning. Everyone says the Agent era is about better prompts, bigger context windows, and smarter retrieval. That is true — but it is not the bottleneck anymore. The bottleneck is memory architecture. Most teams still treat knowledge like a temporary input: retrieve chunks, answer the question, discard the trace. That works for demos. It fails in long-running systems. The same questions get re-solved. The same contradictions get rediscovered. The same context gets paid for, again and again. If an Agent cannot organize, maintain, and evolve what it learns, model strength alone is not enough. You do not get compounding intelligence. You get expensive repetition. That is why I think Knowledge Engineering is now more foundational than RAG tuning alone.…