A Hiring Loop That Actually Tests AI Engineering
Why the standard four-round software loop misses the engineers you actually want — and a concrete loop you can run instead to hire AI engineers at a startup.
The default startup hiring loop — phone screen, two coding rounds, a system design round, and a culture conversation — is calibrated for engineers building deterministic web backends. It does a poor job of separating AI engineers who can ship from AI engineers who can talk about shipping.
What the standard loop misses
- It rewards leetcode fluency that has nothing to do with prompt or eval design.
- It punishes candidates who think probabilistically rather than deterministically.
- It gives zero signal on whether the candidate can debug a hallucinating agent at 2am.
- It ignores judgment about what to evaluate and what to ignore.
A loop that works
We recommend a five-stage loop, calibrated for engineers who will ship AI features end-to-end:
- Stage 1 — Recruiter or founder screen, 30 minutes. Talk about one production AI system the candidate has shipped, in technical detail.
- Stage 2 — Take-home, 3–4 hours, paid. A small, realistic task: build a retrieval or agent prototype against a fixed dataset, then write up the failure modes.
- Stage 3 — Take-home review, 60 minutes. The candidate walks through their solution. Half the conversation is about what they did not build, and why.
- Stage 4 — Eval & debug round, 60 minutes. Give them a broken agent or RAG pipeline. Ask them to find the failure mode and propose a fix.
- Stage 5 — Onsite or virtual final, 2–3 hours. System design (AI-flavored), founder conversation, references.
What you are measuring
The signal you want is judgment under non-determinism: Can the candidate look at a flaky output and form a hypothesis? Do they reach for evals before reaching for prompt tweaks? Do they have a sense of when a problem needs a model upgrade versus when it needs a better retrieval index? Those instincts compound — and they are the difference between an engineer who ships and an engineer who experiments forever.
One more thing
Pay candidates for take-homes. Engineers with shipped AI experience are in demand and will walk from any process that asks for free work. A few hundred dollars and a fast turnaround signal more about how you run your company than any benefits page.