Data Labeling
The companies that recruit and orchestrate domain experts (engineers, doctors, lawyers, PhDs) to author tasks, write rubrics, and grade agent trajectories. Human expert data remains the raw material of most RL environments, and these platforms supply it at scale.
12 startups
| Name | Domains | Location | Team | Funding | Raising |
|---|---|---|---|---|---|
| Anthromind Medical and long-horizon environments and expert data | Medical, Long Horizon, Data Labeling | San Francisco | 1-10 | - | - |
| Besimple AI Human-in-the-loop annotation and evals, with a voice data focus | Data Labeling, Voice, RLHF | San Francisco | 1-10 | ~$3.5M total | - |
| Handshake Career network turned human-data and RL environments provider via Handshake AI | Multi-Domain, Data Labeling, RLHF | San Francisco, New York, Bangalore, Berlin | 250+ | Series F, $200M (2022, ~$3.5B valuation) | - |
| Mercor Expert marketplace powering evals and RL environments for frontier labs | Multi-Domain, Data Labeling, RLHF | San Francisco | 250+ | Series C, $350M at $10B valuation (Oct 2025) | Yes |
| Micro1 Vetted domain experts for AI training data and evals | Data Labeling, Multi-Domain, RLHF | Los Angeles | 101-250 | Series A, $35M at $500M valuation (Sept 2025) | - |
| Pareto Expert data workforce for RLHF, evals, and tool-use environments | Multi-Domain, Tool Use, Data Labeling, RLHF | San Francisco | 26-50 | - | - |
| Rise Data Labs US-based expert human data and custom RL environments for enterprise AI | Computer Use, Coding, Finance, Cybersecurity, Legal, Data Labeling, Enterprise, Multi-Domain, RLHF, Custom Environments | United States | - | - | Yes |
| Scale Data-labeling incumbent extending into agent evals and RL environments | Multi-Domain, Coding, Data Labeling, RLHF | San Francisco, New York, Washington DC, London | 250+ | $1.6B+ raised; Meta invested $14.3B at ~$29B valuation (June 2025) | - |
| Snorkel Programmatic data platform expanding into expert evals and RL environments | Multi-Domain, Coding, Machine Learning, Data Labeling, RLHF | San Francisco, Redwood City, New York | 101-250 | Series D, $100M at $1.3B valuation (2025) | - |
| Surge Bootstrapped human-data leader with a dedicated RL environments org | Multi-Domain, Data Labeling, RLHF | San Francisco, New York, Seattle | 101-250 | Bootstrapped; reported in talks to raise ~$1B at $25B+ valuation (2025) | Yes |
| The LLM Data Company Evals and reward data tooling for LLM training | Machine Learning, Data Labeling, RLHF | - | 1-10 | - | - |
| Turing AGI infrastructure: coding data and RL environments at scale | Coding, Multi-Domain, Data Labeling, RLHF | San Francisco, Palo Alto, Gurugram | 250+ | Series E, $111M at $2.2B valuation (2025) | - |