Contract Marketplace

Finding AI Developers

The hard part is not finding candidates. It is evaluating them when nobody on your team can tell a strong answer from a confident one.

The short answer

  • "AI developer" covers at least three different jobs: building models, integrating existing models into products, and the data engineering underneath both. Most teams need the second and advertise for the first.
  • Be specific about which one you need before you write the posting, or you will interview a research profile for an integration job and conclude the market is thin.
  • Evaluate with a small paid trial on your own problem. For work you cannot assess by reading a CV, a week of real output tells you more than any interview.
  • Ask how they know a system is working. Evaluation discipline separates people who ship reliable systems from people who demo well.

Three roles wearing one label

Model builders. They train and fine-tune models, and their work is research-adjacent. You need this when your problem genuinely has no existing solution, which is rarer than most roadmaps assume.

Applied and integration engineers. They take existing models and build reliable products around them: prompt and retrieval design, evaluation, fallbacks, cost and latency management, and the unglamorous work of handling the cases where the model is wrong. Most commercial projects need this profile.

Data engineers. They build the pipelines both of the above depend on. Many stalled projects are data problems wearing a modelling costume, and this is the hire that unblocks them.

Writing a posting for the first when you need the second is the most common failure here. The candidates you attract will be qualified and wrong, and the ones you need will skip a posting that reads like a research role.

Evaluating without in-house expertise

If nobody on your team can judge the technical answers, stop trying to judge the technical answers. Judge the things you can assess.

Ask how they would know it was working. Strong candidates talk about evaluation early and unprompted: how they would measure quality, what they would do about the cases the system gets wrong, how they would catch a regression. Weak candidates talk about which model they would use.

Ask what they would do when it fails. Every system built on a model is wrong some of the time. Someone who has shipped one has opinions about fallbacks, human review and confidence thresholds. Someone who has only built demos usually does not.

Ask them to explain a past project to a non-specialist. This is not a soft-skills test. Explaining a technical decision in plain terms to somebody who cannot check you is most of the job on a contract engagement, and the ability to do it correlates with actually understanding the decision.

Ask about cost and latency. Production experience shows up here immediately, because both are constraints you only feel once something is live.

Use a paid trial

For work you cannot assess by reading, a short paid trial on a real problem of yours is the highest-information step available. A week, scoped tightly, paid at their normal rate.

What you learn is not only whether the output is good. You learn how they handle an ambiguous brief, whether they tell you when your framing is wrong, and how they report progress on something you cannot verify yourself. On a contract engagement those matter as much as the technical result.

Scope the trial as its own project with its own acceptance criteria. A trial that trails off without a verdict costs you the week and teaches you nothing.

Signals and false signals

Worth weight: shipped systems that stayed live and were maintained; the ability to name what did not work and why; a clear account of how quality was measured; evidence of working within cost and latency limits.

Worth less than it looks: familiarity with a long list of model names, which changes every few months; demos with no evaluation behind them; volume of published side projects, which measures enthusiasm rather than reliability.

Frequently Asked Questions

Most commercial projects need an applied or integration engineer: someone who builds reliable products around existing models, handling evaluation, fallbacks, cost and latency. Model builders who train and fine-tune are needed when the problem has no existing solution, which is rarer than most roadmaps assume. A third group, data engineers, unblock the projects that are really data problems.
Judge what you can assess rather than the technical answers. Ask how they would know the system was working, what they would do about the cases it gets wrong, and how they would catch a regression. Ask them to explain a past project to a non-specialist. Ask about cost and latency, where production experience shows immediately.
For work you cannot assess by reading a CV, a short paid trial on a real problem is the highest-information step available. Scope it tightly with its own acceptance criteria and pay their normal rate. You learn how they handle an ambiguous brief and how they report progress on something you cannot verify, which matters as much as the output.
Familiarity with a long list of model names dates quickly and says little about engineering judgement. Demos without evaluation behind them show what a system can do on a good day rather than what it does reliably. A large volume of side projects measures enthusiasm rather than whether anything stayed live and maintained.

Comparisons

By industry

  • Information Technology
  • Engineering
  • Finance

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