Chapter 13: Patterns in Practice
Patterns are building blocks, not blueprints. Real-world agentic systems typically combine multiple patterns.
Example: An Autonomous Accounts Payable System
Consider a system that processes invoices automatically:
| Pattern | Application |
|---|---|
| Specialisation | Separate agents for invoice processing, vendor matching, and approval routing |
| Pipeline | Invoices flow through extraction → validation → matching → approval |
| Approval gates | Invoices above threshold require human approval |
| Confidence-based escalation | Uncertain matches flagged for review |
| RAG | Agents retrieve vendor contracts and payment terms |
| Supervisor | Coordinating agent monitors pipeline, handles exceptions |
For another real-world example of patterns in combination, see the PIMS asset register case study in Chapter 4 (Runtime Architectures). It demonstrates Tool Use (Pattern 2) combined with Approval Gates (Pattern 11), with a clear graduation path to Confidence-Based Escalation (Pattern 12) — a practical illustration of how organisations often build agentic capabilities within existing applications before recognising them as such.
Designing Combined Pattern Systems
Designing such a system requires:
- Understanding the available patterns
- Assessing your risk tolerance and quality requirements
- Making deliberate choices about where humans stay in the loop
This is where the Pragmatix Agentic AI Maturity Assessment provides value — helping you understand your current state, identify appropriate patterns for your context, and chart a pragmatic path forward.
Looking Ahead
Part 3 covers what it takes to move these patterns from prototype to production — evaluation, security, cost management, and operations.