A UK engineering company that builds what it operates.
PureTensor Ltd designs, commissions and supports private AI and high-performance infrastructure for organisations that need control of their data, their models and their operating environment. We also operate our own Blackwell-generation compute estate in the United Kingdom, as a reference deployment, an engineering laboratory and, where it suits the workload, a managed platform for hosted workloads. The company is founder-led and founder-funded.
Security is run as an operating discipline, not a policy: our own estate is measured every day against a written doctrine, and the ledger is published by Varangian, the security practice of PureTensor Ltd, at varangian.ai.
The company was incorporated in January 2026 (initially under the name Varangian Group Ltd, renamed PureTensor Ltd in March 2026 when the brand was consolidated). Its sole director and controlling shareholder is the founder, Heimir Helgason.
Registered details
- Legal name
- PureTensor Ltd
- Registered in
- England and Wales
- Company number
- 16957867
- VAT number
- GB 514 7995 57
- Office
- 2 Portman Street, Marylebone, London W1
- Registered office
- 71-75 Shelton Street, Covent Garden, London WC2H 9JQ
- Incorporated
- January 2026
- Operations
- United Kingdom (Thames Valley data corridor)
- Disaster recovery
- Iceland
Entity structure
PureTensor Ltd and PureTensor, Inc. (a Delaware corporation headquartered in Mountain View, California) are independent companies under common founder ownership. Neither is a subsidiary of the other; there is no corporate parent. The division of labour is simple: the Ltd builds and operates AI infrastructure for UK clients, including its own compute estate; the Inc is a US research laboratory that publishes its engineering at puretensor.ai.
Two companies exist because two jurisdictions do different work: research partnerships and publishing sit naturally in the US; owning hardware, employing engineers, building systems in client estates and contracting with regulated clients under UK law sit naturally in a UK company. Your contract is with PureTensor Ltd, governed by the law of England and Wales.
Team
PureTensor Ltd is run by the people named on this site. The engineers who design your system are the engineers who build, commission and support it: no outsourced NOC, and no ticket queue between you and them. Founder and team profiles are on the about section of the main page.
We are building the team: platform engineering, field deployment and commissioning, regulated-sector delivery, and operations. Introduce yourself via the contact form.