RLHF & Preference Data
Pairwise judgments and reward signal from verified professionals in-domain — people whose employment records show they've done the work they're grading. Rationales documented, quality audited, identity never in question.
Verified expert workforce · 120 countries
Know exactly who's training your model.
Rainbow staffs RLHF, evaluation, and multilingual annotation from a network of 15M+ professionals we've employed and paid across 120 countries — real roles from real contracts, validated tenure, confirmed languages. We can verify our workforce because we were the employer.
15M+
Professionals employed & paid
120
Countries in the network
10+ yrs
Of ground-truth employment data
180
Countries of payroll & compliance
The difference
A resume is a claim.
A contract is a fact.
Most AI-training talent is vetted with a resume, a LinkedIn profile, and a contractor agreement — none of which confirms what someone actually did, how long they stayed, or whether they were any good at it. We can confirm it, because we were the employer.
Capabilities
All capabilitiesEverything a frontier lab feeds its models.
SFT & Expert Demonstrations
Gold-standard task demonstrations authored by practitioners — diagnoses, briefs, repair procedures, financial analyses — with the reasoning models should absorb, from people we can vouch for by contract.
Human Evaluation & Red-Teaming
Model report cards graded by domain experts with verified credentials: side-by-sides, capability probes, and adversarial passes — with confidence intervals, not anecdotes.
Multilingual & Native-Speaker Data
Dozens of languages staffed by native speakers whose fluency we confirmed from where they actually lived and worked — not a self-ticked checkbox on a marketplace form.
Licensed & Professional Experts
Doctors, nurses, lawyers, insurance and financial-sector specialists, IT professionals, project managers — matched to tasks by the roles and responsibilities in their actual employment contracts.
Trades & Industrial Expertise
Electricians, mechanics, CNC operators, aviation technicians, energy and agriculture specialists, defense-sector engineers — the technical and blue-collar depth most RLHF vendors can't reach through a sign-up form.
Why verification
24,000 fake accounts distilled Claude. Who's behind your labels?
Anthropic disclosed that competing labs used roughly 24,000 fake accounts to distill Claude's outputs — an identity failure on the input side. The same failure mode sits on the human side of every RLHF pipeline: without ground-truth employment data, nobody can confirm who's actually doing the work.
1
Verified identity
The person doing the work is the person we employed — with the record to prove it.
2
Proper employment
Payroll, tax, and benefits through real entities in-country. No 1099 gray zone.
3
Liability with us
If anyone asks who's legally responsible for the workforce, the answer is us — in writing.
Coverage
All regionsReal occupational range, in the regions that carry the workload.
Dedicated operations in every region — not a single annotation role per country, but real occupational range in each.
Europe
ProfessionVerified professionals
- IT professionals & software engineers84,000
- Industrial & manufacturing specialists61,000
- Finance & insurance specialists43,000
- Project managers38,000
- Electricians & energy technicians29,000
Africa — West, East & Central
ProfessionVerified professionals
- Annotation & evaluation specialists41,000
- IT professionals & software engineers23,000
- Finance & mobile-money specialists12,000
- Agriculture specialists & agronomists11,000
- Doctors & nurses7,400
The expert network
Join the networkFrom operating rooms to machine shops.
Doctors, lawyers, and financial specialists — and the electricians, CNC operators, aviation technicians, and agronomists most vendors can't reach through a marketplace sign-up form.
PhysiciansNursesLawyersElectriciansCNC operatorsAviation techniciansMechanicsAgronomistsInsurance specialistsFinancial analystsIT professionalsProject managers
“The first vendor that could tell us — with records, not assurances — exactly who graded our medical evals. Our procurement team had never seen that before.”
“We replaced a marketplace pipeline with their employed pods. Quality went up, attrition went down, and our counsel finally stopped asking about worker classification.”
Writing
All postsFrom the blog.
Rainbow
Introducing Rainbow
We've been running this supply chain quietly behind some of the leading data-annotation companies. Now we're formalizing it — a verified, employed, compliant workforce for AI training.
Rainbow
The 24,000 Fake Accounts Problem
Anthropic's distillation disclosure was an input-side identity failure. The same failure mode is sitting, mostly unexamined, on the human side of every RLHF pipeline.
Rainbow
Your Annotator's Resume Is a Rumor
Self-reported titles are marketing. Contracts, payroll, and tenure are evidence. The difference shows up in your training data.