Moving from a single AI agent to a multi-agent system sounds exciting until you realize your agents have no shared memory, no coordination, and no idea what the other one just did. In this talk, we'll build a multi-agent order management system where specialized agents handle inventory, orders, and delivery, all orchestrated by a manager agent using Hugging Face's smolagents framework. MongoDB Atlas serves as the shared brain, giving agents a persistent state and a document model that naturally fits the nested, unpredictable data that real workflows produce. We'll cover how to define agent tools that talk to a database, how to coordinate multiple agents without chaos, and what happens when an agent fails mid-workflow. You'll walk away with a practical architecture you can adapt to your own multi-agent use case, whether that's order processing, data pipelines, or internal automation.