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Grounded AI for legal, finance and education

4xxi builds AI products on your own trusted content: systems that cite the exact source for every answer and say "no answer" instead of guessing. We work with legal, financial and education organizations, where a wrong answer has a real cost.

  • Min project size
    $10,000+
  • Hourly rate
    $200 - $300 / hr
  • Employees
    2 - 9
  • Locations
    Richmond, England
  • Year founded
    Founded 2008

Overview by:

Reviewer avatar
Evgeny Smirnov
Founder and Lead AI Engineer About the Team

1 Locations

  • Richmond , England

Select Focus Area
Application Platforms
Amazon Application Development Framework
40%
Heroku
20%
AI Technologies & Models
Open AI GPT-3
40%
Anthropic
30%
Cohere
10%
Facebook OPT
10%
Hugging Face Bloom
10%
Digital and IT Strategy Consulting Focus
IT Operations Management Consulting
50%
IT Assessment
20%
Frameworks and CMS
Programming & Scripting
PHP
50%
Ruby
30%
Industries
Legal
35%
Financial services
30%
Education
25%
Information technology
10%
Clients
Midmarket ($10M - $1B)
40%
Small Business (<$10M)
40%
Enterprise (>$1B)
20%

Pricing Snapshot

Min. project size $10,000+
Avg. hourly rate $200 - $300 /hr
Rating for cost 4.8 /5

What Clients Have Said

4xxi offers competitive pricing, with project costs ranging from $17,250 to over $240,000 depending on scope. Clients highlight their exceptional value for cost, with many noting significant savings compared to onshore alternatives. Their commitment to quality and timely delivery enhances their overall value proposition.

This summary is based on verified Clutch reviews.

Most Common Project Size

$50,000 - $199,999 based on 9 reviews
< $49,999 $50,000 - $199,999 $200,000 - $999,999 > $1,000,000

Select a service to see pricing information

Highly Rated Similar Providers

4xxi Review Insights

Overall Review Rating

4.9
  • Quality 4.9
  • Schedule 4.8
  • Cost 4.8
  • Willing to Refer 4.9

Top Mentions

Review Highlights

  • Challenges with Project Management Turnover

    One client reported initial difficulties with project management turnover, which caused challenges until the right fit was found. Since then, the project management has been stable and effective.

  • Responsive and Available Team

    4xxi is noted for their responsiveness and availability, making communication smooth and effective. Clients feel supported and valued, with the team consistently available to address concerns and provide updates.

  • Strong Project Management Skills

    Clients commend 4xxi for their effective project management, marked by excellent communication, timely deliveries, and minimal oversight required from clients. This has contributed to a positive working relationship and successful project outcomes.

  • High-Quality Deliverables

    Clients consistently report satisfaction with the quality of 4xxi's work. The company is recognized for delivering polished, functional, and well-tested products that meet or exceed expectations.

  • Commitment to Client Success

    Reviews highlight 4xxi's dedication to client projects. Their commitment is evident in their drive to understand client needs thoroughly and their enthusiasm for delivering high-quality products.

  • Expertise in Diverse Industries

    4xxi has demonstrated capability across various sectors, including finance, education, and technology. This broad expertise allows them to tailor solutions effectively to different business needs.

4xxi Reviews

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Services
Project Cost
Industry
Location

Mobile App Dev for Social Platform

  • Mobile App Development
  • $200,000 to $999,999
  • Jan. 2020 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They are a fantastic team and we wouldn't be where we are today without them!"

Nov 11, 2020
Director & Co-Founder, Challenge Social
Josh Lewis
Verified
  • Other industries
  • United Kingdom
  • 1-10 Employees
  • Online Review
  • Verified

4xxi was hired by a social platform to redevelop their mobile app for iOS and Android. They were also tasked with coding their website and provide maintenance and support.

Custom Software Development for Advertising Firm

  • Custom Software Development
  • $200,000 to $999,999
  • June 2013 - Sep. 2017
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“I was very impressed by the quality of their work and their development speed.”

Jul 24, 2018
VP of Engineering, Virool inc
Alexander Petrov
Verified
  • Advertising & marketing
  • San Francisco, California
  • 51-200 Employees
  • Online Review
  • Verified

4xxi provided UI development services for various customer dashboards for an online platform. The team created accessible and manageable dashboards for analytics, billing, campaign management, and reports.

Platform Dev for Auditing Firm

  • Web Development
  • Other app platform
  • $50,000 to $199,999
  • Feb. - May 2017
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They can look at a startup from different angles and provide insight on how to improve."

Apr 20, 2018
Owner, Auditing Firm
Anton Petrov
Verified
  • Financial services
  • Russia
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi developed a complex platform for auditing services, handling the programming and design for the whole infrastructure. They provided all documentation and will handle the next version’s build in the future.

Intranet Dev for Private Investment Firm

  • Web Development
  • SQL
  • $50,000 to $199,999
  • Feb. 2015 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“Working with 4xxi has been one of the best commercial experiences of my business life.”

Jan 19, 2018
President, Emanuel Quant Services
Steven Emanuel
Verified
  • Financial services
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi integrated numerous data sources into one tool that displayed all the desired information in a singular report. The project consisted of an iterative and collaborative process.

Web Dev for VPN Firm

  • Web Development
  • JavaScript PHP
  • Confidential
  • Mar. 2017 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

“4xxi builds software to their own quality standards, which are high even compared to Silicon Valley.”

Oct 20, 2017
Director of Product, AnchorFree
Sergey Fedorov
Verified
  • Other industries
  • San Francisco, California
  • 51-200 Employees
  • Phone Interview
  • Verified

4xxi assisted with a VPN website update. The team provided consultation guidance, then collaborated in designing and developing the new platform using PHP and JavaScript.

Web Dev for Financial Services Firm

  • Web Development
  • Ruby React
  • Confidential
  • Oct. 2015 - Ongoing
5.0
Quality
5.0
Schedule
4.5
Cost
5.0
Willing to Refer
5.0

"They are so responsive, thoughtful, great communicators, and really challenge and ask the right questions."

Sep 19, 2017
General Manager, WorthFM
Emily Jipson
Verified
  • Financial services
  • Philadelphia, Pennsylvania
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi built a robo-advisory platform using Ruby and React. They were responsible for project management, backend development, architecture, some design and QA.

Cross-Platform App Dev for Productivity App

  • Mobile App Development
  • Field Operations Mobile App Development Consumer Mobile App Development Enterprise Mobile App Development Android App Development iPhone iOS App Development Hybrid & cross platform apps
  • Confidential
  • June 2013 - Ongoing
5.0
Quality
5.0
Schedule
4.5
Cost
5.0
Willing to Refer
5.0

“We would not be here today if 4xxi was not involved in this project.”

Sep 15, 2017
CEO, Productivity App
Anonymous
Verified
  • Other industries
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi developed a cross-platform app for iOS, Android, and the web. The app is designed for coordinated communication in crisis situations. 

iOS and Android Native Dev for Concierge Service App

  • Mobile App Development
  • Financial Mobile App Development Android App Development iPhone iOS App Development PHP
  • $50,000 to $199,999
  • Aug. 2016 - July 2017
5.0
Quality
4.5
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"[T]hey go that extra mile to answer questions and solve problems."

Sep 6, 2017
CEO, Iterium
Kirill Garbar
Verified
  • Other industries
  • London, England
  • Phone Interview
  • Verified

Using a framework built in PHP and Symfony, 4xxi built mobile concierge apps for the iOS and Android platforms. The projects involved continuous integration, back-end development, and scripting. 

Web Dev for Ratings & Reviews Platform

  • Web Development
  • Other app platform
  • $200,000 to $999,999
  • Sep. 2012 - Ongoing
4.5
Quality
4.5
Schedule
4.5
Cost
4.0
Willing to Refer
4.5

"Within the project guidelines and deliverables they excelled, came up with suggestions and were proactive."

Aug 31, 2017
Former CEO, Industry Index
Gayle Meyers
Verified
  • Advertising & marketing
  • New York City, New York
  • Phone Interview
  • Verified

4xxi acted as the engineering team, building an online platform from the ground up. They provided frontend and backend development and API integration. The platform grew from zero users to over 5,000 users. 

Web Dev for Health & Wellness Sharing Platform

  • Web Development
  • WordPress CMS
  • $50,000 to $199,999
  • July 2016 - Ongoing
5.0
Quality
5.0
Schedule
5.0
Cost
5.0
Willing to Refer
5.0

"They deliver on every aspect they say they are going to.”

Aug 28, 2017
Founder, Nutmeg Asprin
Mara Landis
Verified
  • Other industries
  • New York City, New York
  • 1-10 Employees
  • Phone Interview
  • Verified

4xxi built an AWS and Digital Ocean website, and are currently working on the redesign. They provided feedback to help develop a rewards functionality and encourage a back-to-basics approach for improved UI.

Showing 1-10 of 13 Reviews

Our Story

4xxi was founded by a scientist, and we still work like one: measure first, then build. Our engineers have worked together since 2008 and shipped 100+ products. We believe AI should earn trust, so our systems cite their sources and say "no answer" rather than guess. We stay small and senior on purpose, dive into each client's domain before writing code, and take responsibility for everything we ship. Several clients have stayed with us for over a decade.

Meet the Team

Evgeny Smirnov

Evgeny SmirnovFounder and Lead AI Engineer

Founder and lead engineer of 4xxi, 20 years in software. Working with ML since 2012 and LLMs since 2022, he designed the grounded retrieval architecture behind AAAi ChatBook and Edtek. PhD in mathematics and physics, researching machine learning for

Egor Tomilin

Egor TomilinArchitect and AI Developer

Egor joined 4xxi in 2014 as a back-end developer, led the engineering team, became CTO in 2017. He still designs and builds the systems he is responsible for, with 18 years in software development, from back ends and to AI applications.

Nigel Hopkinson

Nigel HopkinsonDirector

Director of 4xxi since 2018. Previously CEO and VP of Sales at Intuit Services (Europe), SealedMedia and Office Shadow, leading them through one IPO and two acquisitions, then sales director for banking and insurance at SAS.

What Sets Us Apart

Grounded by design

Our AI systems answer only from your verified content, cite the exact source for every claim, and return "no answer" when the data is insufficient. This is how AAAi ChatBook works for the American Arbitration Association.

Fast start, fast prototypes

Kickoff within 3 business days of signing. A deployable prototype in 5 business days. A small senior team means no ramp-up and no handoffs between layers of management.

Low-risk first step

Start with a 2-week Grounded AI audit: accuracy measured on your own data and a concrete plan, or 100% of the fee back. The full fee is credited toward a project signed within 60 days.

Locations (1)

23 Leyborne Park, Kew Gardens, Richmond, Surrey, United Kingdom Richmond, England TW9 3HB

2 - 5

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