About 4xxi
We build grounded AI products on your trusted content — systems that cite their sources and refuse when they don’t know — for legal, financial and education businesses.
- products shipped
- 100+
- raised by our clients
- $500M+
- average client relationship
- 5+ yrs
- building since
- 2008
A small senior team, founded by a scientist, that ships working software in days, not quarters.
We have been building software since 2008, and 4xxi Software Ltd has been a UK company since 2017. The team works across the UK and Europe.
We work with legal, finance and education companies, from start-ups to institutions like the American Arbitration Association.
You talk to the people who build — there is no sales layer, and the founder works on client projects himself. Clients stay with us for 5+ years on average; several have been with us for over a decade.
- Founded by a scientist
- Senior engineers only
- Clients stay 5+ years
- UK company since 2017
The people who build it.
A small senior team. You talk to the people who build — no sales layer. The engineers you meet on the first call are the ones who build your project.
Egor Tomilin
Aleksandr Filippov
Nigel Hopkinson
How we work.
Honesty, integrity and open communication. We take collective responsibility, embrace challenges and value problem-solving.
- 01
Strive for perfection
Healthy perfectionism matters for the products we build. Perfection is not always attainable, but striving for it in 99% of cases is essential.
- 02
Honesty and integrity
We value honesty and transparency. We say what is true and offer genuine solutions, which builds trust and a good working environment.
- 03
Take responsibility
We take responsibility for the outcomes we deliver, recognising that our work is a collective effort. Respecting and valuing our colleagues’ contributions is vital.
- 04
Problem-solving mindset
We embrace challenges and take pride in solving problems, both within our responsibilities and beyond them.
- 05
Open communication
Silence is not the answer. We raise issues and challenges openly so they can be solved. Most problems are tasks that can be resolved.
- 06
Measure before you claim
We work with AI the way a lab works: hypothesis, experiment, measurement. That’s why our systems hold up in production, not only in demos.
- 4xxi Software Ltd
- 10933322
- 25 August 2017
- Registered in England and Wales
- 23 Leyborne Park, Kew Gardens, Richmond, Surrey, TW9 3HB, UK
- Nigel Hopkinson