Scale AI, Inc. is an American artificial intelligence infrastructure and software company headquartered in San Francisco, California. Originally focused on data annotation, the company expanded into reinforcement learning from human feedback (RLHF), large language model (LLM) evaluation, and enterprise software suites for building and deploying AI applications. In June 2025, Meta Platforms agreed to purchase a 49% non-voting stake in Scale AI for $14.8 billion, a landmark investment that underscored the growing importance of data infrastructure in the AI industry.
The company's research arm, the Safety, Evaluation and Alignment Lab, focuses on evaluating and aligning LLMs, and co-created the benchmark Humanity's Last Exam. Scale AI outsources data labeling through its subsidiaries Remotasks (computer vision and autonomous vehicles) and Outlier (LLM data annotation). It also operates an LLM Red Team that conducts human adversarial testing to identify vulnerabilities, biases, and safety risks in AI models, working with organizations such as OpenAI, Google DeepMind, and national AI Safety Institutes.
Founding and Early Growth (2016–2019)
Scale AI was founded in 2016 by Alexandr Wang and Lucy Guo through Y Combinator, after the pair had worked together at Quora. Initial investors included Dragoneer Investment Group, Tiger Global Management, and Index Ventures. Guo was fired in 2018. In August 2019, after Peter Thiel's Founders Fund made a $100 million investment, Scale AI's valuation exceeded $1 billion, granting it unicorn status.
Expansion and Government Contracts (2020–2022)
Scale AI contracted with the United States Department of Defense in 2020. In May 2021, Michael Kratsios, former Chief Technology Officer of the United States under the Trump administration, joined as managing director and head of strategy. By July 2021, the company reached a valuation of $7 billion after a financing round led by Greenoaks, Dragoneer, and Tiger Global, driven by increased demand for data labeling across industries.
In January 2022, Scale AI won a $250 million contract to give American federal agencies access to its suite of tools. In February 2022, the company developed its Automated Damage Identification Service in response to the Russian invasion of Ukraine, analyzing satellite imagery to measure building damage and geotagging reports for humanitarian groups. In November 2022, Scale AI was recognized by Time on its Best Inventions of 2022 list, and opened an office in St. Louis that same year.
LLM Era and Strategic Partnerships (2023–2024)
In January 2023, Scale AI laid off 20% of its workforce. In May 2023, it signed a deal with the US Army's XVIII Airborne Corps, becoming the first AI company to deploy its LLM (known as Donovan) on a classified network. In August 2023, Scale AI became OpenAI's "preferred partner" to fine-tune GPT-3.5, and its services were used to create ChatGPT. That same month, Scale AI's evaluation platform was used at DEF CON's first generative AI red team event, testing models from various companies.
In December 2023, Scale AI contributed to Meta's Purple Llama initiative, a security framework for open generative AI models. In February 2024, the Department of Defense selected Scale AI to test and evaluate its LLMs for military purposes under a one-year contract. In March 2024, Scale reached a valuation of almost $13 billion after a round led by Accel. In May 2024, Scale raised an additional $1 billion with new investors including Amazon and Meta Platforms, bringing its valuation to $14 billion.
In August 2024, Scale signed an agreement with the US AI Safety Institute, part of the Department of Commerce's National Institute of Standards and Technology, to collaborate on research, testing, and evaluation of AI models. In December 2024, a former employee sued Scale AI alleging wage theft and worker misclassification; a second employee filed a similar suit the following month. In January 2025, several contractors sued Scale alleging psychological harm from exposure to disturbing content.
Benchmarks and International Deals (2025)
In January 2025, The Conversation reported that Scale AI and Meta had previously teamed up to create and sell Defense Llama, an LLM product with military-style defense purposes. The company also took out a full-page ad in The Washington Post appealing to President Donald Trump to "win the AI war." Later that month, Scale AI and the Center for AI Safety released Humanity's Last Exam, a benchmark for AI systems. The company also assisted in developing benchmarks EnigmaEval, MultiChallenge, and MASK.
In February 2025, Scale AI agreed to a five-year partnership with the Qatari government to improve government services via AI tools and training, including predictive analytics, automation, and advanced data analytics. The deal was signed at the Web Qatar 2025 Summit by Mohammed bin Ali bin Mohammed Al Mannai, Qatar's Minister of Communications and Information Technology. Also in February, Scale became a third-party evaluator of AI models for the US AI Safety Institute.
In March 2025, Scale AI reached a multimillion-dollar deal with the Department of Defense to develop the Thunderforge project, a "major step in U.S. military automation." The project aims to use AI to plan and help execute movements of ships, planes, and other assets, speeding up military decisions in peace and wartime. The contract, awarded by the Defense Innovation Unit to Scale AI, Anduril Industries, and Microsoft, is intended to first be used with USINDOPACOM and EUCOM. In April 2025, Scale AI released Scale Evaluation, a platform for testing LLMs against benchmarks to pinpoint weaknesses and flag where additional training data would improve the model.
Meta's $14.8 Billion Investment (June 2025)
On June 10, 2025, it was reported that Meta Platforms had agreed to purchase a 49% non-voting stake in Scale AI for $14.8 billion. The company would remain a standalone, independent entity from Meta. As part of the deal, CEO Alexandr Wang took a top position inside Meta and was replaced by Jason Droege, the company's chief strategy officer and former Uber executive. This investment marked one of the largest single-company stakes in an AI infrastructure firm, reflecting Meta's strategy to secure high-quality training data and evaluation services for its large language models.
Scale Labs and Future Directions
In March 2026, Scale AI launched Scale Lab, an initiative aimed at advancing research and development in AI safety and evaluation. The lab is expected to build on the company's existing work with the Safety, Evaluation and Alignment Lab and its collaborations with government agencies and industry partners. Scale AI's continued expansion into defense, government services, and enterprise AI tools positions it as a central player in the AI infrastructure ecosystem, with Meta's investment providing substantial capital for future growth.
See Also
- Artificial intelligence
- Machine learning
- Generative AI
- OpenAI
- Google DeepMind
- Amazon Web Services
- Anthropic
- Data augmentation
- RLHF
- Model pruning
References
This article is based on publicly available information and reports from June 2025. Specific details about Scale AI's operations and investments are drawn from company announcements and reputable news sources.