Checklist
The six-layer AI architecture checklist
Twelve yes/no checks across the six layers of a production AI feature, two per layer. The model sits inside only one of them.
I'm starting to see the same gap in a lot of AI features. The demo works, and production never arrives. The model is rarely the reason. An AI feature is six layers, and the model sits inside only one of them. These twelve checks cover all six, two checks per layer.
From the talk: Your AI feature is an architecture problem
The twelve checks
Two per layer, in the order a request passes through them. A yes counts only when the control runs in code today.
Each yes scores one point.
- 1.The AI feature works inside the signed-in user's permissions. Layer 1, product interface. It calls the same APIs as the rest of the product, so it can't read or change more than the person using it.
- 2.The interface says it's AI and marks what it generated. Layer 1. A notice where people talk to the system, and a machine-readable mark on generated content (art. 50(1) and 50(2) Regulation (EU) 2024/1689).
- 3.Every request passes authentication and validation before a prompt exists. Layer 2, access and policy. Size limits, schema checks, and rate limits run in ordinary code, ahead of the model.
- 4.A policy step removes or pseudonymises the personal data a task doesn't need. Layer 2. Data minimisation in practice (art. 5(1)(c) Regulation (EU) 2016/679). The model sees a token, and our own system swaps the real value back in.
- 5.Retrieval reads only the sources we approved. Layer 3, context retrieval. A named list of data sources, each with an owner. A new source goes through review like a code change.
- 6.The retrieval service applies the tenant filter in code. Layer 3. The tenant ID comes from the authenticated session. A prompt that says "only this customer's data" isn't a control.
- 7.Every model call goes through one gateway. Layer 4, model gateway. Our code talks to one interface. The gateway holds the EU-region endpoints, the quotas, the retries, and the model routing.
- 8.The feature still works when the model is slow or down. Layer 4. A queue, a timeout, and a rules-based fallback. A failed model call delays a suggestion and never blocks the core product.
- 9.An evaluation set from real cases scores every change. Layer 5, quality checks. It runs in CI on each prompt or model change, and a lower score blocks the merge.
- 10.A named person approves the outputs that matter. Layer 5. Anything that moves money, changes a record, or reaches a customer waits for a human or a deterministic rule.
- 11.Every request leaves a trace we can query. Layer 6, operate safely. The request ID, the model and prompt version, the retrieved sources, and the approver, in a log the feature can't edit.
- 12.We know what one AI action costs, per customer. Layer 6. Tokens, model, and cache hits per request, joined to the tenant. Pricing and plan limits rest on that number.
What the score means
| Score | Where we stand |
|---|---|
| 11 to 12 | Ready for a customer's security review. The work now is keeping the evaluation set and the traces current. |
| 8 to 10 | Close. A layer with two noes is the one I'd expect to break first. |
| 0 to 7 | I'd start with layers 2 and 3. A leak of personal data, or of another customer's data, is the mistake that's hardest to undo. |
Where each industry feels it first
The three patterns from the talk are the same six layers, with a different pair under the most pressure.
| Industry | Pattern | Layers under the most pressure | The question a customer asks |
|---|---|---|---|
| Finance | The model proposes, the ledger decides. | 5 and 6: approval and an audit trail. | Why did the system decide this, and who approved it? |
| Healthcare | Sensitive data never reaches the model raw. | 2 and 4: redaction and EU residency. | Where does a patient's data go after it enters the feature? |
| B2B SaaS | Tenants stay isolated at retrieval, and every AI action has a cost. | 3 and 4: tenant isolation and cost. | Can another customer's data ever show up in my answers? |
What I leave out on purpose
I leave out fine-tuning, an agent framework, a dedicated vector database, and a self-hosted model. None of them fixes a missing layer. Each one is easy to add once the evaluation set shows the need.
Next step
I highly recommend bringing your score and the one AI feature on your roadmap to a thirty-minute call. I'll show which layer I'd expect to break first, and whether the problem is the one it looks like. Which layer scored zero for your team?
Book a callThese takeaways are an engineer's reading of the rules and the tools. I wrote them to help teams decide what to build. They aren't legal advice. I recommend checking the current text with your own counsel before planning around a date or a threshold.
How I help
Cloud security hardening
I find the gaps in your cloud accounts, identity, network, and data, rank them by what an attacker reaches first, and close them with your team.
AI integration
I put language models to work on the problems that matter in your product and back office, and I ship them to production.
Other takeaways from this talk
Template
AI decision log template
A copy-ready log for AI features that touch money or records: what the model proposed, what it saw, and who or what approved it.
Worksheet
AI data-path map
A one-page worksheet that follows personal data through an AI feature, stop by stop, with the eight leak paths I check first.
Worksheet
Cost per AI action worksheet
A worksheet and a SQL query that turn tokens, model prices, and request logs into a cost per AI action and per customer.
Let's talk.
A 30-minute call, no pitch. We look at your current setup, your stage, and the thing that's bothering you about it. I give a straight opinion on what to change, what to leave alone, and whether the problem is the one it looks like. What's the one thing in your stack you'd fix tomorrow?
Prefer email or phone? hello@netninjas.eu or +31 6 45984313
