Course resource
AI Stack Architecture Template
How the pieces of your AI setup fit together, and how to document it so someone else can maintain it.
The four layers
INTERFACE where you and your team interact with it
ORCHESTRATION what decides the sequence and connects the parts
INTELLIGENCE the models doing the judgement
DATA what it knows and where that lives
Most stacks fail at the data layer — not because the models are weak, but because the model cannot see what it needs, or sees a stale version.
Your stack
Interface
| Where work arrives | Who uses it | Notes |
|---|---|---|
| Chat assistant | ||
| Chat platform bot | ||
| Forms | ||
| Scheduled, no interface |
Orchestration
| Tool | What runs there | Why this tool |
|---|---|---|
If you have more than two orchestration tools, ask why. Splitting workflows across platforms is the main reason nobody can debug them later.
Intelligence
| Job | Model tier | Temperature | Why |
|---|---|---|---|
| Classification / routing | cheap, fast | 0–0.2 | |
| Extraction | cheap, fast | 0–0.2 | |
| Drafting for humans | capable | 0.5–0.7 | |
| Final customer-facing output | capable | 0.5–0.7 | |
| Bulk / high volume | cheapest that works | 0–0.3 |
The rule: use the cheapest model that passes your quality bar for each step, not the best model for everything. A classification step does not need a frontier model, and running one there is most people's largest avoidable cost.
Data
| What it knows | Where it lives | Who updates it | Last reviewed |
|---|---|---|---|
Connections
Draw or list every connection. For each, the two questions that matter:
| From | To | What flows | Contains personal data? | What happens if it fails |
|---|---|---|---|---|
The "what happens if it fails" column is what turns a diagram into a working system.
MCP, in one paragraph
Model Context Protocol is the emerging standard for how an AI connects to tools and data. Instead of a bespoke integration per tool per platform, a tool exposes an MCP server once and any MCP-capable client can use it. The major automation platforms now support it on both sides — exposing your workflows as tools an agent can call, and letting your workflows call external MCP servers.
Practically: it means the connection layer of your stack is becoming standardised, and a tool you wire up once is reusable across assistants. Worth designing toward rather than building more one-off integrations.
The principles
Own the portable parts. Your prompts, your documents, your processes. If those live somewhere you control, swapping the model or the platform underneath is an afternoon. If your work only exists inside one vendor's format, you are locked in.
Put the human where the risk is. Not everywhere — that defeats the point — but before anything that reaches a customer, moves money, or writes to a system of record.
Log the judgement steps. Every AI step should record its input and output. Without this you cannot debug anything, because the same input may not reproduce the same failure.
Design for the model changing. It will. Keep prompts in one place rather than scattered through workflow steps, so a model swap is one edit.
Fail loudly. Silent failure is the default in automation and the worst property a stack can have.
The single-point-of-failure audit
| If this breaks | What stops | How I find out | Fallback |
|---|---|---|---|
| The orchestration platform | |||
| The model provider | |||
| One specific integration | |||
| The person who built it |
That last row is the one people never fill in, and it is the most common failure in practice.
Documentation
Someone else should be able to run this without you. At minimum:
- A diagram or list of what connects to what
- Every workflow named, with one sentence on what it does
- Where the prompts live
- Where the credentials live, and who can rotate them
- What to do when each thing breaks
- Monthly cost, and what drives it
- Named owner, and a review date
Review
| Date | What changed | Cost | Anything retired |
|---|---|---|---|
Retiring things matters. Stacks accumulate workflows nobody uses, still running, still costing money.