# Agent System Engineering
Agent System Engineering is the discipline of leveraging [[AI Agent Harness|agent harnesses]] to create agentic systems that achieve meaningful goals, efficiently, either in isolation (single agent) or through collaboration (with humans, other agents, or both).
Where [[Harness Engineering]] focuses on equipping, guiding, and steering individual AI models with tools, rules, permissions, and skills, agent system engineering operates at the system level: designing how agents are composed, coordinated, and orchestrated to accomplish complex, multi-step objectives.
## Relationship to other disciplines
| Discipline | Scope | Focus |
|---|---|---|
| [[Prompt Engineering]] | Single interaction | How to phrase the question |
| [[Context Engineering]] | Information environment | What reaches the model |
| [[Harness Engineering]] | Individual agent | How the agent runs |
| [[Intent Engineering]] | Goal definition | What must be accomplished |
| **Agent System Engineering** | Multi-agent system | How agents work together |
Harness engineering is a prerequisite. You need well-harnessed individual agents before you can compose them into reliable systems. Agent system engineering then addresses the emergent complexity of multi-agent collaboration.
## Key concerns
- **Agent composition**: which agents exist, what each is responsible for, and how they're specialized (cfr [[AI Agent Identity]])
- **Orchestration**: how agents are coordinated, sequenced, or parallelized (cfr [[AI Agent Orchestration]])
- **Routing**: how tasks are dispatched to the right agent (cfr [[AI Agent Routing]], [[Receptionist AI Design Pattern]])
- **Memory and state**: how knowledge persists across agents and interactions (cfr [[AI Agent Memory]])
- **Communication**: how agents share information, delegate work, and report results (cfr [[AI Subagents]])
- **Panels**: how groups of agents evaluate content from multiple perspectives (cfr [[AI Agent Panels]])
- **Governance**: permissions, audit trails, human-in-the-loop checkpoints
## Architecture patterns
- **Single-agent with tools**: one agent orchestrates everything via tool calls and [[Model Context Protocol (MCP)|MCP]]
- **Multi-agent pipeline**: agents arranged in sequence, each handling a stage
- **Multi-agent swarm**: agents operating in parallel with coordination (cfr [[AI Agent Swarms]])
- **Hierarchical delegation**: a supervisor agent delegates to specialized sub-agents
- **Human-in-the-loop**: agents execute within boundaries, escalating to humans when needed
## The microservices analogy
The agentic AI field is going through its microservices revolution. Single all-purpose agents are being replaced by orchestrated teams of specialized agents, just as monolithic applications gave way to distributed service architectures. This brings similar challenges: coordination complexity, observability, and the need for clear contracts between components.
## References
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## Related
- [[Harness Engineering]]
- [[Context Engineering]]
- [[Intent Engineering]]
- [[AI Agents]]
- [[AI Agent Harness]]
- [[AI Agent Orchestration]]
- [[AI Agent Routing]]
- [[AI Agent Identity]]
- [[AI Agent Memory]]
- [[AI Agent Skills]]
- [[AI Agent Panels]]
- [[AI Agent Swarms]]
- [[AI Subagents]]
- [[Receptionist AI Design Pattern]]
- [[How coding agents work]]
- [[Agentic Engineering]]
- [[Levels of AI use]]
- [[Agentic Knowledge Management (AKM)]]
- [[Claude Code]]
- [[SOLID Principles]]
- [[Loose Coupling]]
- [[Composition over Inheritance]]
- [[Software Design Patterns for AI Skills and Agents]]