Most agent frameworks in 2024 and early 2025 treated orchestration as an afterthought. You had a single agent with a toolbox, a system prompt, and a task. The assumption was that one agent, given enough context and tools, could solve any problem in a single conversation thread.

This assumption breaks at scale. Not because the models aren't capable enough — they often are — but because single-threaded agents have an inherent architectural ceiling: they can only do one thing at a time, they carry the full context of everything that's happened, and they have no way to delegate or parallelize.

The shift happening now

The pattern emerging in production AI systems is the agent manager: a coordinator agent whose job is not to do the work directly, but to decompose tasks, dispatch them to specialized sub-agents, and synthesize the results. Think of it as the difference between a solo developer and a tech lead with a team.

This matters for three reasons:

• Specialization: Sub-agents can be optimized for their specific task — different models, different context windows, different tool access.
• Parallelism: A manager can dispatch multiple sub-agents simultaneously and wait for results, rather than doing things sequentially.
• Context management: Each sub-agent carries only the context relevant to its task. The manager carries the high-level state. This is dramatically more efficient than one agent accumulating 100K tokens of context.

The design challenges nobody talks about

Multi-agent systems are more capable and harder to debug. The failure modes are non-obvious: a sub-agent that confidently returns a wrong answer, a manager that fails to notice the sub-agent misunderstood the task, a loop where agents keep delegating without converging.

The evals problem is significantly harder in multi-agent systems. You need to evaluate not just the final output, but the coordination behavior. Did the manager decompose the task correctly? Did it choose the right sub-agents? Did the synthesis preserve the important parts of each result?

These are solvable problems. But they require treating multi-agent coordination as a product problem, not an infrastructure problem.