Reference stack layers
| Layer | Purpose | Key questions |
|---|---|---|
| Orchestration | Coordinates model calls, tools, retries, and fallbacks | Can we enforce policies centrally? |
| Workflow engine | Runs deterministic business steps around AI tasks | How are approvals and exceptions handled? |
| Data & retrieval | Indexes and retrieves governed knowledge | Can we trace source provenance? |
| Observability | Monitors quality, latency, and cost | Do we detect regression quickly? |
| Policy controls | Applies compliance, redaction, and access rules | Who can change rules and when? |
Build vs buy guidance
Buy for speed when requirements are standard; build selectively for proprietary logic, strict sovereignty needs, or deep ERP/CRM process coupling.
Recommendation: standardize telemetry and policy interfaces first so tooling can evolve without replatforming core workflows.