Quick answer: Full-stack AI engineering is the practice of building an AI feature from end to end: the data and retrieval layer, the model and orchestration layer, the application interface, and the production monitoring that keeps it working. It treats a model as one component inside a larger system rather than the product itself. I’ve spent the past few years watching teams move from “we called an LLM API and shipped a demo” to “we run this thing in production, and it can’t fall over on a Tuesday.” The gap between those two states is where full-stack AI development actually lives.