AI that holds together outside the demo.
Agent systems and automation with the parts that decide whether they survive contact with real users: what the model is allowed to touch, what goes into its context, what happens when it is wrong, and how a prompt or model change gets checked before it ships.
The systems this fits.
AI product work is where a lot of the demand sits. It is also where the gap between a convincing demo and an operable system is widest.
- An AI feature that works in a demo and has not been trusted with real users yet.
- An agent that needs to take actions in real systems, where the question is what it must never be able to do.
- A workflow with genuine repetition in it, where the judgment stays with a person and the mechanics should not.
- An existing AI surface that changes behaviour unpredictably when a prompt or a model is updated.
- A product where retrieval quality, not model choice, is what actually decides whether the answers are good.
Where AI systems actually break.
Rarely in the model. They break in the layer around it: the tool an agent could call but should not have been able to, the context window quietly truncating the one document that mattered, the retrieval step returning plausible neighbours instead of the right passage, the integration that fails open and lets a bad action through.
The second failure is that nobody can tell whether a change made things better. Without a fixed set of cases and a procedure for running them, a prompt edit ships on the strength of looking better in the one example somebody tried, and the regression surfaces a week later in a user's account.
The third is permissions. An agent inherits whatever credential was convenient, which is usually one with far more reach than the task needs. The blast radius of a mistake gets decided by an implementation detail rather than by anyone's decision.
The stack, and where this sits.
The model occupies one rung. Almost every failure this category exists to answer happens on the rungs around it.
A reference architecture, meaning the shape the work is designed to rather than a record of systems delivered. It names layers and responsibilities and never products: what runs at a given layer is a decision taken with you during scoping, not one taken here in advance.
- L5
Product surface
Coverage: TouchedThe surface an AI feature answers through, taken as far as the feature needs. A full product build is its own category.
- L4
Services and APIs
Coverage: OwnedAgent and workflow orchestration: the steps, the state between them, and what happens when one of them fails.
- L3
Data and state
Coverage: OwnedContext and retrieval design, built against the questions the system actually has to answer, and the data movement between the systems it touches.
- L2
Models and agents
Coverage: OwnedExplicit tool and permission boundaries, defined failure paths, and the evaluation harness a prompt or model change is checked against. The work is the system around the model, not the model.
- L1
Runtime and infrastructure
Coverage: TouchedWhat the system runs as, and where its state lives between steps, taken as far as the system needs. Building the platform itself is its own category.
- L0
The layer underneath
Coverage: OutsideCredential handling and the blast radius of a mistake continue in security and systems depth, which is where that work is scoped.
What the marks mean
- Owned
- This category is accountable for the layer. It is designed, built and handed over inside the engagement.
- Touched
- The work reaches the layer as far as the build needs it to, and the depth here belongs to one of the other categories.
- Outside
- Deliberately not this category. The note on the rung says where the work goes instead.
What the engagement produces.
The parts that make an AI surface operable rather than impressive.
- Agent and workflow orchestration: the steps, the state between them, and what happens when one fails.
- Explicit tool and permission boundaries: what the system may read, write and call, decided and written down.
- Context and retrieval design, built against the questions the system actually has to answer.
- An evaluation plan and harness: the cases it is measured against, and the procedure for checking a change before it ships.
- Guardrails and defined failure paths, including what the system does when it is not confident.
- The data movement between the systems this touches, with the boundaries the data crosses made deliberate.
What you are no longer exposed to.
The failure modes that put an AI feature in front of a customer before it was ready.
- Shipping a change to an AI surface on the strength of it looking better in a demo.
- An agent that can reach a system nobody intended it to reach, because it inherited a credential rather than being granted one.
- Behaviour that changes without warning when a model version moves underneath you.
- A failure path discovered by a user rather than designed by an engineer.
- Automation that moves the work somewhere else instead of removing it.
Work turned down.
The AI requests that are better answered by saying no.
- A demo intended to raise money rather than serve users. It is a legitimate thing to want and it is not what this is.
- Model training or fine-tuning as the headline. The work here is the system around the model; where a fine-tune is genuinely the answer, that gets said during scoping.
- An AI feature with no defined success condition, where nobody can say what a good answer looks like. That is a product question, and it comes first.
- Replacing judgment that should stay with a person. Automation is aimed at the repetitive mechanics, not at the decision.
- Anything that needs a benchmark number published before the system exists to measure.
What you are left holding.
An AI system nobody can evaluate is one you cannot safely change.
The evaluation plan, and the harness that runs it
What the system is allowed to do, what it must never do, the cases it is measured against, and the procedure for checking a prompt or model change. Your team runs it after we are gone; that is the point of it.
The permission model, written down
What every agent, job and integration may read, write and call, and why. A control that can be traced back to its reason can be reviewed. One that cannot gets guessed at and eventually widened.
Prompts and context in source
Versioned in your repositories alongside the code, not pasted into a console. A prompt is a behavioural decision and it belongs under the same review as any other one.
The known limitations
Where the system is weak, which inputs it handles badly, and what was deliberately left out of scope. Stated plainly, because the alternative is your team rediscovering each one.
The reasoning behind this.
The document, the build and the process this page draws on.
- DocumentsSample artifactsThe AI evaluation plan is one of the eight formats, shown with what it records and the risk it removes.
- BuildA natural-language analytics systemThe data and inference build: carrying raw events to a number worth acting on without failing silently.
- ServiceSecurity and systems depthWhere the agent boundary work continues: least privilege, credential handling and the blast radius of a mistake.
Start with the constraint.
Describe the AI surface and what it is allowed to touch. The first useful answer is usually about boundaries, not models.