Preference Model

Founded in 2018 and headquartered in San Francisco, Labelbox is an AI data and agent infrastructure company offering Horizon (RL environments for frontier labs), Recursion managed agents for enterprises, and the Alignerr expert network for labeling, evaluation and human feedback.

Proximal, founded in fall 2025 in San Francisco, describes itself as a data research lab that builds complex, long-horizon reinforcement learning environments and evaluation data for frontier AI labs and enterprises. It started with coding-agent training data and is expanding into drug design, chip design and legacy software modernization; it also released the open benchmark FrontierSWE.

Fleet (fleetai.com), founded in 2024 and based in New York, builds high-fidelity reinforcement-learning environments that replicate enterprise software such as Salesforce and Excel plus browser/desktop workflows, so frontier AI labs and enterprises can train and evaluate computer-use agents. Founder and CEO Nicolai Ouporov was a founding engineer at Respell (acquired by Salesforce).

Micro1, founded in 2022 in Palo Alto, California, helps AI companies source and manage human contractors for data labeling and model training.

Contra is a San Francisco-based commission-free marketplace that connects independent professionals such as designers and developers with clients. Through its Contra Labs division it connects its creative-talent network with frontier AI labs for creative RLHF annotation, benchmarking, evaluation and post-training data.

Abundant (YC F24, founded 2024, San Francisco) provides on-demand expert human operators that handle AI agent edge cases via API with auditable decision records, and builds agent simulation / reinforcement-learning environments and datasets for AI labs; it says it serves three of the six leading AI labs and several Fortune 500 companies.