Lead AI engineering, fractional

The work

Builds the systems that put models into production and keeps them there.

Fractional means you carry a decision, not a backlog. Hirers who want a pair of hands are pointed at a project instead.

The bar

You have owned delivery and you have set the standard others worked to, including saying no to work that was already funded.

Why this one is hard to judge. A demo proves nothing. What matters is what they did when it failed under real load.

What we ask to see

• A system you put into production and kept there, with the failure that taught you the most
• What you changed after that failure, and how you knew it worked
• Code, an architecture note, or a design document we can read

One solid item beats five vague ones. A referee we can actually call beats a link to a landing page.

What gets an application declined

• The only evidence offered is a certification, a course, or a job title
• Every piece of evidence is under an NDA and no sanitised version or referee is offered
• The work described is entirely a demonstration, a proof of concept, or a hackathon
• More than six disciplines are claimed, which we read as a signal that none has been assessed

If we decline you, the reason is written down and sent to you. The software refuses a decline without one.

What it pays

£400 to £788 a day. That is the tenth to ninetieth percentile of what UK employers advertised for the closest published titles over the six months to 8 August 2026.

Advertised UK contract day rates for Machine Learning Engineer, Artificial Intelligence, tenth to ninetieth percentile, six months to 8 August 2026. Advertised, not agreed, and set by the hirer rather than by us.