Fractional AI CTO — ownership and how to verify it

What the role owns

A fractional AI CTO is a senior operator who holds end-to-end accountability for an AI product or platform on a part-time retainer: problem framing, architecture, delivery, cost, risk and the handoff to your staff. At LMXAI that person is the founder — an AI engineer and consultant in Leiden — acting as the single throat to choke across software, data, serving and commercialisation.

Ownership is not “available for Slack.” Ownership is: the production path has a name on it, the eval suite has a name on it, and when the model regresses someone is already on the hook.

How to verify ownership (buyer checklist)

1. Repository access. You hold the org. They work in it. No “we’ll export later.”
2. Running system. Staging or production URL, not only a recording.
3. Evaluation artefacts. A dated report: retrieval hit rate, tool-success, failure cases. If there is no eval, there is no ownership of quality.
4. Runbooks. How to rotate keys, update weights, disable a tool, and who to call at 02:00.
5. Cost sheet. GPU or API spend tied to traffic assumptions, reviewed monthly.
6. Risk register. Data classes, AI Act tier, and the human gate — written down.
7. Staffing plan. Who inside your company takes which pager after the engagement.

Workshops, capability maps and vendor bake-offs are inputs. They are not verification. If a candidate cannot show the seven items above from a prior engagement (redacted), they are selling advice, not ownership.

	Hire a Head of AI	Staff-aug team	Fractional AI CTO (LMXAI)
Time-to-first production	Slow (recruit + ramp)	Medium	Weeks, if scope is honest
Accountability	High, once hired	Diffused	Named, contractual
Cost shape	Full-time fully loaded	Many juniors	Senior hours, no theatre
Best when	AI is a standing department	You already have a strong lead	You need a lead and the first system

When not to hire fractional

If you need a people-manager for a 20-person ML org, hire full-time. If you need a one-week workshop with no production mandate, do not call it CTO. Fractional works when a company must ship a sovereign or production system and does not yet have a leader who has done it.