TypeSafe AI

TypeSafe AI was founded in 2024 by Diogo Almeida, who serves as chief executive; its co-founders are chief technology officer Erik Gafni and chief operating officer Sasha ShengSasha ShengSasha Sheng is a software engineer and entrepreneur, co-founder and chief operating officer of the artificial intelligence company TypeSafe AI. She worked on mobile apps and machine learning systems at Yahoo and Facebook (Meta), won a number of AI hackathons after leaving Meta, and in 2024 co-founded TypeSafe AI with Diogo Almeida and Erik Gafni.Open the full entry. Almeida previously worked at OpenAI on reinforcement learning from human feedback (RLHF), InstructGPT, ChatGPT, and GPT-4; the leadership team’s backgrounds span OpenAI, Google Brain, and Meta FAIR.⁠[1][2][2][3]

The company then spent about two years developing in stealth. Almeida wrote that at OpenAI he helped build the methods that made language models good at following instructions and talking with people, but he came to believe that chat models were missing something important, which led him to ask: models have been superhuman at chat for years, so where is all the automation?⁠[4][4][4][4]

Before leaving stealth, the company published “The Bitterest Lesson” on its blog, arguing, on the basis of Rich Sutton’s “bitter lesson,” that in machine learning choosing the right task matters more than data, compute, and algorithms; the next day it published a further essay criticizing “benchmaxxing,” the practice of optimizing for public benchmark scores.⁠[5][5][6][6]

On September 15, 2026, TypeSafe AI came out of stealth and released its first System One model, Jev, opening it through an early-access waitlist; at the same time it announced a $40 million seed round led by the deep tech venture capital firm DCVC. A person familiar with the transaction put the round’s valuation at about $200 million.⁠[4][4][4][7][1][3]

The company defines System One models as a new class of models built for decisions inside software: they take unstructured program state as input and return typed values in a structure defined in advance (such as yes/no, a choice from a list, or a score on a scale), with calibrated probabilities and confidence attached to every decision, so that developers can set when the software should act automatically and when it should hand a case to a person for review. The model uses a new architecture, a parallel sampler, and a training method called Reinforcement Learning for Calibrated Decisions (RLCD), and it does not generate strings.⁠[8][1][8][4][4]

At launch the company’s published price was $0.042 per million input tokens ($42 per billion tokens), with output tokens free of charge; end-to-end response times were 70 to 500 milliseconds. The company said that in its workflow evaluations Jev was 193.6 times faster and 444.6 times cheaper than the language models it was compared with, and noted that these figures came from workflows written by its internal team and were likely at the high end of real-world gains; the figures have not been independently verified.⁠[4][4][4][4][1]

The name “System One” comes from the fast, intuitive “System 1” thinking described in Daniel Kahneman’s Thinking, Fast and Slow; Jev is named after the economist William Stanley Jevons, reflecting the company’s expectation that machine intelligence will follow the path of coal after improvements in steam-engine efficiency, with falling costs leading to rising demand.⁠[4][4][4]

James Hardiman, a general partner at lead investor DCVC, said TypeSafe was addressing “one of the biggest remaining challenges in AI”: making models reliable enough to embed in products at scale.⁠[1]

On September 28, 2026, Andreessen Horowitz released a podcast conversation between Ben HorowitzBen HorowitzBen Horowitz is an American entrepreneur, venture capitalist and business author who co-founded Andreessen Horowitz (a16z) with Marc Andreessen in 2009. He previously led Loudcloud’s transition into Opsware and its 2007 sale to Hewlett-Packard. His writing and investing address startup management, organizational culture and the relationship between technology and cultural industries.Open the full entry, Martin CasadoMartin CasadoMartin Casado is a computer scientist, entrepreneur and venture capitalist who is a general partner at Andreessen Horowitz, where he leads infrastructure investing. A major proponent of software-defined networking, he co-founded Nicira and served as its chief technology officer, and after VMware acquired the company he ran its networking and security business; he also co-founded the nonprofit MuralNet.Open the full entry, and Almeida. On the show Almeida argued that coding agents help people write software faster, but that the software they produce works much as software always has; TypeSafe’s approach is to put intelligence inside software itself, so that programs can understand intent and make probabilistic decisions.⁠[9][9][9]

On October 7, 2026, the company published a customer case study: within 10 days of its first test, the talent marketplace Jack & Jill switched all calls for a key stage of its candidate-matching pipeline from Gemini 3.1 Flash Lite to Jev; according to the company, accuracy stayed the same, cost fell by 88%, completion time was about 50% faster, and projected savings were $500,000 a year.⁠[10][10][10][10]

On October 9, 2026, TypeSafe AI announced an $870 million Series A at a $7.5 billion valuation, led by Andreessen Horowitz with participation from Sequoia Capital, existing investor DCVC, and a group of angel investors; Martin Casado joined the company’s board. The company said that a third of the Fortune 500 were using Jev and that it had already saved customers millions of dollars in production.⁠[11][11][11][11][11]

The same day, Andreessen Horowitz published an investment announcement co-signed by Jennifer Li, Sarah WangSarah Wang (a16z)Sarah Wang is a venture capitalist and general partner on the growth team at Andreessen Horowitz (a16z). She joined a16z in 2019 and leads growth-stage investments in AI, enterprise applications and infrastructure, having invested in companies including Character.AI, Wiz, Cursor, Temporal and Exa.Open the full entry, Martin Casado, Marc AndreessenMarc AndreessenMarc Andreessen is an American entrepreneur and venture capitalist, a co-founder and general partner of the venture capital firm Andreessen Horowitz (a16z). While in college he helped develop the graphical web browser Mosaic, then co-founded Netscape and Loudcloud (later renamed Opsware), and has long served as a director of Meta; he has also published essays such as “Why Software Is Eating the World.”Open the full entry, and Ben Horowitz, calling the Jev launch “the biggest narrative violation we’ve seen this year” and the fastest-growing model they had ever seen, having generated 1 trillion tokens within 3 days of launch; according to a16z, thousands of use cases appeared in Jev’s first week, and 25% of Fortune 500 enterprises had integrated Jev.⁠[12][12][12][12][12]

In the announcement a16z argued that the real economic unlock should be for all software to carry the intelligence of the latest models natively, at performance and cost consistent with traditional software economics; Jev costs roughly 1/100 to 1/500 as much as frontier models and is about 100 times faster on classification tasks at comparable accuracy. The announcement coined the “Jev-ons paradox”: make intelligence cheap enough to call anywhere, and it gets called everywhere. It also said that AI should make software more powerful rather than just automate the recreation of existing software, and that “the true bitter lesson” is not about building a new being but about returning the primitives of intelligence to builders. The announcement closed with the line “Software continues to eat the world.”⁠[12][12][12][12][12][12]

On October 14, 2026, the company released jev-1.14.0 and, behind “danger zone” request headers, opened experimental features including image input, a box type that returns a single bounding box, and longer context, noting that these features were not yet recommended for production; the company said the new version’s largest gain was in multilingual support, planned to point jev-latest to it a week later, and said it would give 60 days’ notice before deprecating the older version.⁠[13][13][13][13][13][13][13]

As of October 2026, the company’s enterprise page stated that it had a SOC 2 Type II report, offered zero data retention to enterprise customers, and did not use customers’ prompts or other inputs to train or fine-tune models.⁠[14][14][14]

TypeSafe AI: Official website: https://typesafe.ai/ (opens in a new window).⁠[8]

X: Public account: https://x.com/typesafeai (opens in a new window)⁠[8]

LinkedInLinkedInLinkedIn is a social networking platform for professionals. It was founded in 2002 by Reid Hoffman and others, launched in 2003, and listed on the New York Stock Exchange in 2011; after Microsoft acquired it for approximately $26.2 billion in 2016, it became a wholly owned Microsoft subsidiary. Its revenue comes from membership subscriptions, advertising, and recruitment solutions.Open the full entry: Public profile: https://www.linkedin.com/company/typesafe-ai/ (opens in a new window)⁠[8]