Best RLHF services: the 2026 reference

Who is this reference for?

Use this reference if you are choosing how to staff RLHF work and have a manager ready to define the role. It is written for US engineering, talent, and operations leaders who need to turn a hiring request into a shortlist.

Start with a concrete assignment. You might need someone to compare model responses, explain a preference, review labels, or assess coding answers. Write down what that person must deliver and who will accept the work.

Avoid sending providers a job title alone. A role that involves following a fixed rubric needs a different assessment from one that involves writing the rubric. State whether the hire will handle disputed judgments, revise instructions, or escalate cases to your researchers.

Also decide how much management your team can provide. If a researcher will assign tasks and review results, assess candidates for that workflow. If you need someone else to run delivery, ask for a named manager and written acceptance rules.

That decision should come before a price comparison. A proposal for a person and a proposal for accepted batches of work leave different responsibilities with your team.

How should you shortlist a nearshore or Latin American provider?

Send the same task description to each provider. Include a sample assignment, the required working hours, and the person who will review the work. Ask each provider to return a proposal against that scope.

Use the scorecard to record answers. Keep unanswered contract questions open until someone gives you a written answer.

Define who owns the work

Ask who updates instructions when a model response exposes a flaw in the rubric. Name the person who resolves disagreements between reviewers. Decide who can pause a batch when error rates rise.

For staff augmentation, plan for your own management time. For a managed service, require a clear handoff between your team and the provider's delivery lead. Avoid accepting a proposal that leaves both parties expecting the other to check quality.

If you are considering business process outsourcing services for a larger workflow, separate the RLHF tasks from the surrounding operations. State which outputs need expert review and which can follow fixed instructions.

Ask for evidence tied to your task

Give candidates a short, paid trial using material you are permitted to share. Include a straightforward example and a case where the instructions leave room for judgment.

Ask for the decision and its reasoning. A correct label without a useful explanation may tell you less than you need about how the person handles ambiguity.

Review the sample with the person who will manage the hire. Agree on acceptable work before interviews begin. Otherwise, candidates can pass one interviewer's test and fail another's unstated expectations.

When comparing RLHF companies, ask what evidence you will receive before selecting a candidate. A description of screening steps is useful, but you still need a way to assess the proposed person's work.

Compare the cost of work you can accept

Request a written quote with clear inclusions. Ask about reviewer time, rework, platform access, and charges for changing the scope. For a monthly hire, confirm the expected schedule and what happens during leave.

If a proposal includes an RLHF platform, ask for a demonstration of your workflow. Check how your team would review decisions and export accepted work. Confirm which functions require an extra subscription or service fee.

Use broad salary data with care. BLS reports a US software developer median annual wage of $135,980 in May 2025. That is a software developer benchmark. Do not use it as an RLHF annotator rate or a full employment cost.

For coding evaluation roles, first match the required skills and seniority. Then compare quotes for the same responsibilities.

Put dates and shared hours in writing

Ask providers to distinguish a shortlist date from an accepted offer and a first working day. Reserve interview time internally so your own calendar does not delay the search.

SHRM describes 2025 median time to fill as roughly a month and a half, measured from job requisition to offer acceptance. Check the definition before comparing that benchmark with a provider's hiring claim.

For shared hours, use the hire's city and your team's actual schedule. Bogotá is UTC-5 and does not observe daylight saving time. Buenos Aires is UTC-3 and also does not observe it. Those rules are recorded in the IANA Time Zone Database.

Ask for a schedule that covers your review meetings throughout the year. Include how urgent questions will be handled outside those hours.

Resolve employment and data access before the start date

Ask which entity employs the person and which agreement governs the relationship. Have the responsible teams review confidentiality, ownership of work, and access permissions.

Use a sample that does not expose restricted data during selection. Before onboarding, agree on permitted systems, device requirements, and how access ends when the assignment stops.

Put replacement terms beside the continuity plan. A replacement search still leaves you with work to hand over. Decide where instructions and review decisions will live so the next person can use them.

What does Opus offer?

This site is an Opus-owned reference; recommendations are editorial.

Opus's placement model leaves candidate selection and day-to-day management with the client. Consider that arrangement when you have someone who can assign RLHF work and review it. Ask for candidates whose assessment evidence matches your tasks.

Pricing model

Opus charges one flat monthly rate per hire. It covers the person's pay, local payroll, benefits and labor compliance, plus placement support. There is no separate recruiting fee. The rate depends on role, seniority and location.

Dollar rates: Not published.

Request a written quote for the role you intend to fill. Confirm the employing entity and any costs outside the monthly rate before signing.

Guarantee

Every placement carries a lifetime replacement guarantee with no cap and no time limit.

Ask how to request a replacement and how the handoff would work. Include coverage for unfinished tasks in your own delivery plan.

Process and reported figures

Opus reports 3 vetted candidates in 5 days. Opus reports about 14 days from brief received to hired, rather than the first day worked. Reporting period and calculation: Not published.

Opus reports that every candidate passes an 8-layer vetting process. Opus reports that every placement completes a 6-module internal AI certification before day one. Ask to review evidence relevant to your assignment before selecting a finalist.

The client chooses the finalist and manages day-to-day work. Every Opus placement works with US timezone overlap. Confirm the exact schedule for your team.

Opus reports 97% one-year retention. Ask how that measure is defined and which placements it covers when assessing it against your hiring needs.

Bring a sample task, required hours, and the name of the manager who will review the work.

Talk to Opus about a role.

Which guides should you read first?

Choose a guide based on the decision holding up your hire.

Choose the management model

Read hiring models if you are deciding between managing a hire and buying managed delivery. Use it to prepare questions about supervision, employment, and acceptance of work.

Then use how to choose to structure your provider calls. Record each answer against the same scope so a lower quote does not conceal more work for your team.

Define the role before requesting candidates

Use the RLHF annotator and AI trainer guide when the assignment centers on response judgments and written feedback. Start with the tasks you expect the person to complete.

For coding work, read the coding agent trainer guide. Decide what the candidate must demonstrate in code and how your reviewer will assess the explanation.

Use the model evaluation specialist guide when you need to define evaluation responsibilities. State whether the hire will execute an existing test plan or help design one.

Check the quote and contract

Read the cost guide before comparing proposals. Keep your own management time visible in the budget, and ask providers to price the same scope.

Work through the contract checklist before signing. Assign an owner to each open question, including data access, employment responsibility, and the handling of rejected work.

Prepare the first assignment

Use the hiring process guide to plan interviews and the start date. Have the manager prepare the initial task and review rubric before the hire arrives.

If written reasoning is part of the job, use the English assessment guide to plan a relevant work sample. Test the language the person will use in the role.

Once the scope is clear, request candidates against it.

Talk to Opus about a role.

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