How to vet staff augmentation engineers: a 10-step checklist

To vet staff augmentation engineers, vet two things separately: the vendor's process and the specific person who will join your team. Write the role down first, interview the exact engineer you will get (not a stand-in), test them on work that looks like your backlog, check references, and get the vendor's substitution, replacement, exit and IP answers in writing before you sign.

The 10-step vetting checklist

1. Write the role brief: stack, seniority bar, first-90-day scope and reporting line.
2. Set your overlap requirement: how many hours a day the engineer must be online with your team, and in which time zone.
3. Ask the vendor how they source and test: each stage, and the pass rate if they publish one.
4. Confirm security and access practices: whose accounts the engineer works in, NDAs, and how access is revoked.
5. Interview the named engineer yourself: the person on the profile is the person who starts.
6. Run a technical exercise that matches the job: live coding, a short take-home or a code review.
7. Add system design for senior roles: trade-offs, failure modes and scaling decisions in your domain.
8. Test communication: spoken English in the interview, written English in a PR description or design note.
9. Check references: a former manager or tech lead, with specific questions.
10. Get terms in writing and scope a first-week task: substitution, replacement, notice and IP terms, plus a defined first ticket that shows how the engineer works.

Before you talk to vendors

A vague brief produces a vague shortlist. Vendors match against what you give them.

Define the role by the work, not the title

"Senior backend engineer" means different things at different companies. Write down what this person will actually do in the first 90 days: the services they will own, the integrations they will build, the on-call rotation they will join. Our job description templates are a fast starting point.

Set the seniority bar in observable terms

Describe seniority as behavior you can test: can design a service from a one-page spec, can review other engineers' pull requests and catch real problems, can work through an ambiguous ticket without daily check-ins, has run something in production and been paged for it. That list becomes your interview rubric. If you use a leveling ladder, map the role to it so the vendor and your team mean the same thing.

List the stack with versions and must-haves

Separate the must-haves (TypeScript, React 18, PostgreSQL, AWS with Terraform) from the nice-to-haves (GraphQL, Kafka). A padded must-have list shrinks the pool; a short one that hides a real requirement causes a mismatch in week two.

Decide your overlap hours

If your team pairs, holds daily standups and expects same-day code review, you need most of the working day in common. Put a number on it, such as "online 9 AM to 5 PM Eastern," and use the time-zone overlap calculator to check candidate locations against your team's hours.

Vetting the vendor

The vendor's process determines who reaches your shortlist. Ask these questions on the first call and push for specifics.

• How do you source candidates? Referrals, recruiters, job boards or an existing bench each produce a different pool.
• What does each stage test? A good vendor can name the stages and what each one measures: background review, a structured technical interview, communication, availability. "We have a rigorous process" is not an answer.
• What share of candidates pass? If the vendor publishes a pass rate, ask how it is measured and out of how many candidates. If they don't publish one, don't demand a number they would have to make up; ask instead what most candidates fail on.
• Who does the engineer report to day to day? It should be your engineering lead. If a vendor-side manager sits in between, you are buying a different service.
• What are your security and access practices? Ask whether engineers work in your accounts (your GitHub, your cloud, your SSO) or on vendor infrastructure, whether they will sign your NDA, how devices are secured, and how quickly access is removed when someone rolls off. You should be able to revoke access yourself at any time.

Vetting the engineer

The vendor's screening narrows the pool. Your interview decides whether this person fits your team. Keep it to two or three hours of the candidate's time.

Technical interview

Start with their recent work. Ask them to walk through a system they built: the architecture, why they chose it, what broke and what they would change. People who did the work can go three levels deep; people describing a team's work get vague fast. Our interview questions by role cover common stacks.

Live coding vs take-home

For the code review exercise, give a real-looking pull request of 150 to 300 lines from your stack with a mix of issues: a missing index, an unhandled error path, a race condition, a confusing name, and a test that doesn't test anything. Strong engineers rank them by impact.

System design for senior roles

For senior and lead roles, give a design problem from your domain: "design the service that ingests 10,000 webhook events a minute from three payment providers and guarantees each is processed once." Look for clarifying questions first, sensible defaults, explicit trade-offs (queue choice, idempotency keys, retries, observability), and an honest answer to "what fails first?"

English and communication

Remote work runs on writing. Test both modes: the spoken conversation in the interview, and something written, like the explanation attached to a take-home or a short design note. Ask them to explain a technical decision to a non-engineer.

Reference checks

Ask for a former manager or tech lead, not a peer. Ask specific questions: "What did they own end to end?", "How did they handle a production incident?", "Would you hire them again, and for what kind of role?" Hesitation on the last question is the most useful signal you will get.

A scoped first-week task

Before the engineer starts, pick one real ticket they can finish in the first week: a contained bug, a feature behind a flag, or a test suite for an untested module. It shows how they ask questions, open a pull request and respond to review. Grant repo, CI and cloud access before day one so the task can start on day one.

7 mistakes buyers make (and how to avoid them)

1. Interviewing only the vendor's pick. One candidate gives you nothing to compare against. Ask for a shortlist of two or three for each role, and interview them against the same rubric.
2. Allowing candidate substitution. The bait-and-switch: you interview a strong engineer and a different person shows up. Require that the engineer you interview is the named person who starts, and put that in writing.
3. Skipping a trial or early checkpoint. You won't know how someone works until they work on your code. Ask each vendor whether they offer a paid trial or a defined early review period, what it costs and what happens if it doesn't work out. If there is no formal trial, set your own 30-day checkpoint with written criteria.
4. Signing inflexible terms. Long minimum commitments and long notice periods turn a bad fit into an expensive one. Ask about notice periods, ramp-down and how to scale the team up or down before you sign.
5. Vetting the resume instead of the work. Technology lists are easy to pad. A code review exercise and a system walkthrough reveal more than any list of frameworks.
6. Ignoring overlap and communication until week two. A strong engineer who is offline for your standups and reviews slows the whole team. Confirm hours as a schedule and test writing in the interview.
7. Onboarding with no access and no first task. Many "bad hires" spent week one waiting for credentials. Prepare access, a buddy and a scoped first ticket before day one.

Questions to ask before you sign

Ask every vendor the same questions, compare the answers side by side and get the important ones in writing.

How Ryz vets engineers

We've interviewed tens of thousands of engineers, and only the top 1% make it. Our recruiters source candidates, ARC, our in-house ranking system, orders the pipeline, and every candidate completes a structured NTRVSTA AI interview so each person is assessed the same way. AI scores are advisory: recruiters review every candidate before and after the interview and build the shortlist. The full process is on our vetting process page.

• We scope the role with you first: stack, seniority, the hours of overlap you need and what a strong first few months look like.
• We test for four things: technical depth, communication, ownership and time-zone fit. Our engineers are based in Latin America and work on US business hours, including New York hours.
• You meet named engineers before the engagement starts. You get a recruiter-curated shortlist with the names of the people, you run the final interview, and you choose who joins.
• Your code, your accounts. You own all code and IP our engineers produce. We'll sign your NDA before we share profiles or start work, and engineers work in your repos, cloud and tools, with access you control and can revoke at any time.
• A fast start. Engineers can start in under two weeks once you say go, and most of our engineers ship code in their first week.

Ryz engineers work on your team, reporting to your leads, at $7,000 to $15,000 per engineer per month depending on seniority. Ryz is not the right fit if you want a self-serve freelance marketplace or a trial before talking to anyone, or if you need engineers in Europe or Asia time zones. Read more about staff augmentation at Ryz, or talk to us to scope your team.

Related

• What is staff augmentation?
• How to hire remote developers
• Staff augmentation vs freelancers
• Job description templates

FAQ

How do I vet a staff augmentation developer?

Write a role brief with the stack, seniority bar and overlap hours, then interview the named engineer yourself. Use a technical exercise that matches the job (live coding, a capped take-home or a code review), add system design for senior roles, test written and spoken communication, check references with a former manager, and give a scoped first-week task.

What is candidate substitution in staff augmentation?

Candidate substitution, or bait-and-switch, is when you interview one engineer and a different person starts. Prevent it by requiring in writing that the engineer you interview is the named person who joins, and that any change needs your approval and a new interview.

Should I ask for a paid trial with a staff augmentation vendor?

Ask every vendor whether they offer a trial or an early review period, and get the length, cost and outcome terms in writing. If there is no formal trial, set your own 30-day checkpoint with written criteria and confirm the notice period in case the fit isn't right.

Is live coding or a take-home test better for vetting remote engineers?

Neither is better in general. Live coding shows how someone reasons in real time; a capped take-home shows code structure and tests; a code review exercise is often the most revealing for senior roles. Pick the format that looks most like the job.

What questions should I ask a staff augmentation company before signing?

Ask whether the engineer you interview is the one who starts, what happens if they aren't the right fit, the notice period to end or scale down, whether a trial is available, who owns the code and IP, and the monthly rate by seniority.

How does Ryz vet engineers?

Recruiters source candidates, our ARC system ranks the pipeline, and every candidate completes a structured NTRVSTA AI interview, with recruiters reviewing each person before and after. Only the top 1% of the tens of thousands of engineers we've interviewed make it, and you meet named engineers from a recruiter-curated shortlist before anything starts.

Questions we didn't answer? Email info@ryzlabs.com.