5 Layers of Prompt Injection Defense You Can Wire Into Any Node.js App

Taking an AI agent from demo to production requires solving six critical challenges: config and model governance, state and memory design, security boundaries, evaluation pipelines, and operational monitoring. Prototype failures follow predictable patterns — broken state, leaked secrets, unchecked tool access, and zero observability. This guide gives engineers a concrete framework for building agents that survive real traffic, real failures, and real adversarial inputs.