Multi-Agent Systems and Agentic AI Architectures
“A single agent can solve a task. A team of agents can solve a business problem.”
Introduction
In Part 7, we learned that an AI agent can:
- Reason
- Plan
- Use tools
- Maintain memory
- Execute tasks
But enterprise systems rarely rely on a single component.
We don’t build one giant Java class.
We build:
- Controllers
- Services
- Repositories
- Message consumers
- External integrations
Similarly, modern AI systems are evolving toward:
Multi-Agent Systems
Instead of one intelligent agent doing everything, multiple specialized agents collaborate.
Why One Agent Is Not Enough
Imagine asking:
Review my architecture, identify risks, analyze costs, evaluate security, and recommend improvements.
A single agent must become:
- Architect
- Security expert
- Cloud expert
- Performance expert
- Financial analyst
This often leads to:
- Long prompts
- Reduced accuracy
- Higher hallucinations
- Poor specialization
Software Engineering Analogy
Monolithic agent:
One Agent
├── Security
├── Architecture
├── Cost
├── Compliance
└── Operations
Microservice agents:
Architecture Agent
Security Agent
Cost Agent
Operations Agent
Compliance Agent
Sound familiar?
What is a Multi-Agent System?
Multiple AI agents collaborate to solve problems.
Each agent has:
- Responsibilities
- Tools
- Memory
- Goals
Example
User:
Review my AWS architecture.
Agents:
- Architecture Agent
- Security Agent
- Cost Agent
- Operations Agent
Final answer combines all results.
Architecture
User
↓
Supervisor Agent
/ | \
/ | \
Architecture Security Cost
Agent Agent Agent
\ | /
\ | /
Final Report
Why Multi-Agent Systems Work
Benefits:
✅ Separation of concerns
✅ Specialized knowledge
✅ Independent tools
✅ Better reasoning
✅ Parallel execution
✅ Easier maintenance
Agent Roles
| Agent | Responsibility |
|---|---|
| Planner | Break tasks |
| Researcher | Gather information |
| Reviewer | Validate results |
| Summarizer | Produce output |
| Executor | Run actions |
Example: Project Review
User:
Review our microservice architecture.
Planner:
- Analyze architecture.
- Check security.
- Evaluate costs.
Architecture Agent:
- Service boundaries
- APIs
Security Agent:
- Authentication
- Authorization
Cost Agent:
- Infrastructure spending
Supervisor:
- Consolidate findings
Supervisor Pattern
Most common enterprise pattern.
User
↓
Supervisor
↓
Workers
↓
Results
↓
Supervisor
↓
Answer
Example
Supervisor:
Analyze application.
Delegates:
- Security review.
- Performance review.
- Scalability review.
Advantages
- Central control.
- Easy monitoring.
- Clear responsibilities.
Team Pattern
Agents collaborate equally.
Agent A ↔ Agent B
↕
Agent C ↔ Agent D
Example:
- Research agent
- Validation agent
- Writing agent
Debate Pattern
Two agents disagree.
Example:
Agent 1:
Use Kafka.
Agent 2:
Use RabbitMQ.
Judge:
Select the best solution.
Hierarchical Pattern
CEO Agent
↓
Manager Agents
↓
Worker Agents
Large organizations may eventually adopt this approach.
Blackboard Pattern
Agents share information.
Shared Knowledge Base
↑
Multiple Agents
Example:
- Architecture findings
- Security findings
- Cost findings
Agent Communication
Agents exchange:
- Messages
- Context
- Results
Example:
{
"risk": "Database bottleneck",
"severity": "HIGH"
}
State Management
Multi-agent systems maintain:
Goal
Current Tasks
Completed Tasks
Failures
Results
Example
Architecture Review
✓ Security Completed
✓ Cost Completed
✗ Performance Failed
Retry Required
Enterprise Example
Architecture Review Platform
Agents:
Architecture Agent
Reviews:
- Services
- APIs
- Boundaries
Security Agent
Reviews:
- Authentication
- Secrets
- Vulnerabilities
Cost Agent
Reviews:
- AWS spend
- Scaling costs
DevOps Agent
Reviews:
- CI/CD
- Monitoring
- Deployment
Final Report
Supervisor combines:
- Risks
- Recommendations
- Action items
Parallel Execution
Traditional:
Security
Cost
Performance
Sequential.
Multi-agent:
Security ─┐
Cost ─┼── Parallel
Performance┘
Faster execution.
Memory in Multi-Agent Systems
Each agent may have:
Local Memory
Its own context.
Shared Memory
Common knowledge.
Example:
Project:
Spring Boot
Cloud:
AWS
Messaging:
Kafka
All agents can access this.
Tool Specialization
Architecture Agent:
- Vector database
- Documentation
Security Agent:
- Vulnerability scanner
Cost Agent:
- AWS billing APIs
DevOps Agent:
- Kubernetes APIs
Human-in-the-Loop
Not every decision should be autonomous.
Example:
Agent:
Ready to deploy.
User:
Approved.
Agent:
Proceed.
Important for:
- Banking
- Healthcare
- Finance
Agent Failures
Problems:
- Infinite loops.
- Conflicting answers.
- Wrong tools.
- High costs.
Guardrails
Limits:
- Maximum steps.
- Maximum tokens.
- Tool permissions.
- Approval workflows.
LangGraph
One of the most important frameworks for agents.
Concept:
Node
↓
Decision
↓
Next Node
Example
User Question
↓
Retrieve Documents
↓
Analyze
↓
Need More Information?
↓
Yes → Search Again
No → Respond
State Graph
START
↓
Planner
↓
Research
↓
Review
↓
END
Why Graphs?
Because AI workflows are not always linear.
Example:
Search
No Result
Search Again
Review
Respond
Agentic Workflows
Traditional software:
step1();
step2();
step3();
Agent workflow:
Observe
Think
Act
Evaluate
Repeat
Enterprise Use Cases
1. Architecture Copilot
Agents:
- Architecture
- Security
- Performance
2. Production Support
Agents:
- Logs
- Metrics
- Incidents
3. Banking
Agents:
- Fraud
- Compliance
- Risk
4. HR Assistant
Agents:
- Leave
- Payroll
- Benefits
Example: Incident Analysis
User:
Production failed.
Supervisor:
- Logs Agent.
- Metrics Agent.
- Deployment Agent.
Final report:
- Root cause.
- Recommendations.
Java Analogy
| Java Architecture | Multi-Agent |
|---|---|
| Microservices | Agents |
| Orchestrator | Supervisor |
| REST Calls | Agent Communication |
| Shared DB | Shared Memory |
| Workflows | Agent Graphs |
| BPM | Agent Plans |
Cost Considerations
Multiple agents mean:
- More LLM calls.
- More tokens.
- More latency.
Optimization becomes important.
Observability
Track:
- Agent execution.
- Tool calls.
- Token usage.
- Errors.
- Response time.
Interview Questions
What is a multi-agent system?
Multiple AI agents collaborating.
Why use multiple agents?
Specialization and scalability.
What is the supervisor pattern?
One coordinator manages workers.
What is LangGraph?
A framework for agent workflows.
Why use human approval?
Risk reduction.
Hands-On Project
Enterprise Architecture Reviewer
Agents:
- Architecture Agent
- Security Agent
- Cost Agent
- DevOps Agent
Input:
- HLD
- LLD
Output:
- Risks
- Recommendations
- Action plan
Future Enterprise Architecture
Imagine:
Developer
↓
Architecture Agent
↓
Security Agent
↓
Cost Agent
↓
Deployment Agent
↓
Production
This may become normal software delivery.
Key Takeaways
✔ Agents specialize.
✔ Supervisors coordinate.
✔ Teams collaborate.
✔ LangGraph manages workflows.
✔ Shared memory improves results.
✔ Guardrails are essential.
✔ Multi-agent systems resemble distributed systems.
What’s Next?
Part 9 — LangChain and LangGraph for Java Architects
Topics:
- What is LangChain?
- Chains.
- Retrievers.
- Memory.
- Tools.
- Agents.
- LangGraph.
- State management.
- Workflow orchestration.
Because understanding these frameworks helps us build production-grade AI systems instead of isolated experiments.
“Monoliths became microservices. Chatbots are becoming multi-agent systems.”