For software engineers familiar with microservices, AI agents can seem like an entirely new architectural world, filled with unfamiliar concepts such as tools, context, memory, planning, grounding, and behavioral evaluation. Yet many of the engineering concerns behind agent systems, including clear responsibilities, well-defined interfaces, coordination, state management, permissions, resilience, and observability, have familiar counterparts in distributed software architecture. The key is knowing where those comparisons are useful and where they break down, since agents interpret goals and choose actions in ways traditional services do not. This article uses microservices as a learning bridge to explain the core concepts of agent development, helping experienced engineers build on what they already know while understanding what must be learned on its own.