Most startup founders chase revenue charts, headline funding rounds and polished stage presentations. Alexander Kardos-Nyheim took a different route. While training as a solicitor at Allen & Overy, he built Safe Sign Technologies, a legal-specific large language model (LLM) startup designed to make artificial intelligence more reliable for legal work. Roughly two and a half years after its founding, Thomson Reuters acquired the company before it had generated revenue from subscriptions. The acquisition, announced on 21 August 2024, demonstrated how specialised research and technical expertise can create value before a business has paying customers. The story raises a question every founder, investor and legal professional should consider, what truly makes a young company valuable? From a teenage planning dispute to an unusual acquisition, Kardos-Nyheim’s journey offers a closer look at the changing economics of artificial intelligence.
How a teenage planning dispute at Rollins House in south-east London shaped a future startup founder
The story begins long before any startup existed. According to a first-person commentary published by Fortune, the house where Kardos-Nyheim grew up, Rollins House, was a run-down Art Deco former factory in south-east London. His mother lived there, and a developer wanted to redevelop the site into flats. The family could not afford lawyers, so, while still at school, he taught himself planning law between bouts of exam revision. He examined records that others had overlooked and assembled a dossier of precedents. Facing a council panel across the table from an experienced law firm, he presented the family’s case, and they won. The experience taught him the value of detailed research, persistence and challenging assumptions, lessons that would later influence his approach to legal technology.
Training as a solicitor at Allen & Overy by day and building a startup at dawn and every night
Years later, that determination was tested in a far more demanding setting. Kardos-Nyheim trained as a solicitor at Allen & Overy while developing Safe Sign Technologies outside working hours. He began at half past four in the morning, working on the company before a full day of legal training, then returned to the startup each evening. By his own account, the arrangement was not sustainable, even though the firm was tolerant of it. Separately, the company often came close to running out of cash and needed new funding to keep going. Its initial idea, a consumer-facing legal product, also failed to attract investors, forcing the team to rethink its direction. Instead of building another legal service, the company turned towards the underlying technology, artificial intelligence models trained specifically for legal reasoning and research.Kardos-Nyheim’s background combined legal training with an understanding of the difficulties faced by people trying to navigate complicated rules and documents. That combination became central to Safe Sign’s identity. The Law Gazette’s report on the acquisition identifies him as a Cambridge law graduate and former trainee solicitor at A&O Shearman, the firm formed through the combination of Allen & Overy and Shearman & Sterling.
Alexander Kardos-Nyheim (Image: City of London School)
Securing capital from North American investors after British investors repeatedly said no
Funding proved equally difficult. Local investors repeatedly turned him down, according to his account in Fortune, so Kardos-Nyheim travelled to New York with only £200 to his name. The effort paid off, with nearly all of the company’s capital eventually coming from North America rather than the UK. He observed a difference in the questions investors asked, American backers were more likely to explore how they could help, while British investors tended to focus on how the venture might fail.Once the company had enough funding to continue, the team abandoned the immediate pursuit of revenue and concentrated on building its proprietary artificial intelligence models. Its researchers were drawn from institutions including the University of Cambridge, the Massachusetts Institute of Technology, Harvard University and DeepMind. The objective was not simply to add an AI chatbot to an existing legal service, but to develop models specifically for the demands of legal work.This was a difficult proposition to sell. Developing specialised LLMs requires considerable research, testing and technical expertise, while commercial returns can take time to emerge. Investors expecting rapid sales were therefore less receptive to a business whose principal asset was still under development; by Kardos-Nyheim’s account, most lost interest. Safe Sign nevertheless continued to prioritise the technology, betting that reliability and domain-specific performance would eventually distinguish it from general-purpose AI systems.
Thomson Reuters acquires a pre-revenue artificial intelligence startup in an unusual deal
The research-led strategy ultimately attracted a major buyer. On 21 August 2024, Thomson Reuters announced its acquisition of Safe Sign Technologies, describing the UK business as a developer of legal-specific large language models. Based on its own internal assessment, the company said Safe Sign’s models had demonstrated industry-leading performance in domain-specific evaluations, and that the acquisition would help accelerate the development of its CoCounsel AI assistant. The price was not disclosed.The deal was particularly notable because Safe Sign had no subscription revenue when it was acquired. Kardos-Nyheim describes it as Thomson Reuters’ first pre-revenue acquisition in its 174-year history. The acquisition came about two and a half years after the startup’s founding in early 2022, bringing its research team into a much larger organisation with established legal content, products and subject-matter expertise.The strategic appeal went beyond the startup’s existing products. Legal professionals need AI systems that can handle complex questions while minimising confident but incorrect answers. By combining Safe Sign’s specialised research with Thomson Reuters’ legal information and professional expertise, the company aimed to improve the quality and reliability of AI-assisted legal work. The deal showed how a young business can attract a major acquirer through its intellectual property, research capabilities and specialist team, even before its technology has produced conventional commercial returns.
Why substance can outweigh pitch decks in the race to develop specialised artificial intelligence
Kardos-Nyheim’s experience also offers a broader lesson for founders and investors. A polished presentation and early revenue figures do not necessarily reveal the full value of a technology business. In fields such as artificial intelligence, a company’s underlying research, technical expertise and ability to solve difficult problems may matter more than its immediate sales.The challenge is distinguishing a genuinely defensible technology from an idea that can easily be replicated. In legal AI, reliability is particularly important because errors can affect professional decisions and the people relying on them. Safe Sign’s focus on legal-specific models reflected the view that general-purpose AI systems may not automatically meet the demands of high-stakes professional work.The company’s acquisition also illustrates why specialist AI research can appeal to established technology businesses. Thomson Reuters already possessed extensive legal information and professional products; Safe Sign brought expertise in developing models for the legal domain. Bringing those capabilities together offered a route towards AI systems tailored to the needs of lawyers and other professionals.For early-stage founders, the lesson is not that revenue no longer matters. Rather, a business can create value before reaching that milestone if it develops technology that solves a clearly defined problem and demonstrates why its approach is difficult to reproduce. For investors, the task is to look beyond a pitch deck and assess the substance behind the claims. And for the legal profession, the acquisition reflects a growing emphasis on AI that combines technical capability with domain knowledge, accuracy and trust.Rollins House, where the story began, remains a reminder of how an early experience with a complex legal dispute helped shape Kardos-Nyheim’s interest in the field. Years later, that interest had developed into a specialist AI company whose research attracted one of the world’s major legal information and technology businesses.
