UX Strategy & Design Leadership
Define a UX vision that aligns user needs with business goals — then lead the team that delivers it.
European Accessibility Act · Full-lifecycle UX
The Accessibility Act is in force. Is your product exposed?
Digital products and services sold in the EU are now expected to be accessible. UXellence finds the gaps, fixes them at the root, and turns compliance into a product that simply works better — for everyone. Led by Matthaios Mantzios, who wrote the guide to WCAG 2.2, Section 508 and the EAA.
Writing & ideas featured in
UX PlanetFast CompanyThe Decision LabAmazon · AuthorADPList · Mentor
Beyond compliance
Accessibility is the floor. A product people actually use is the goal.
An audit tells you what's broken. It doesn't tell you why users abandon the form, why support tickets pile up, or why the redesign didn't move the number. UXellence works the whole chain — research, strategy, information architecture, design systems and interface — so the fix holds. And because one senior partner carries the work end to end, nothing is lost in the handoffs between vendors.
What the work produced
94%
All-time-high satisfaction across a telecom's web touchpoints
40%
Fewer overdue payments after a billing & self-service redesign
5M+
Accounts on a national digital-identity platform
Client names withheld by agreement. Full context on the Work page.
Trusted across industries
Selected organizations Matthaios has worked with across telecom, publishing, public sector, media and academia.
University of Cambridge
Judge Business School Cambridge
University Press European
Environment Agency COSMOTE COSMOTE Insurance Netcompany-Intrasoft ITML ANT1
Judge Business School Cambridge
University Press European
Environment Agency COSMOTE COSMOTE Insurance Netcompany-Intrasoft ITML ANT1
Services
The full UX discipline, one senior lead
User Research & Usability Testing
Interviews, usability testing and behavioural analysis that turn evidence into confident product decisions.
UX/UI Design
Intuitive, engaging interfaces — wireframes and prototypes through to production-ready design.
Information Architecture
Structure content and navigation so complex products feel effortless to use.
Design Systems
Scalable systems that keep products consistent and accelerate delivery across teams.
Accessibility Consulting
WCAG 2.2 and EAA audits. A clear path from wherever you stand: a free readiness self-check, a fixed-scope assessment, ready-made compliance documents, or a full audit of the whole product.
Selected work
Senior UX, measurable outcomes
A selection of engagements across the sectors UXellence knows best. Client details are kept confidential; the outcomes are real.
A single digital identity at national scale
Owned the product vision for a telecom's unified authentication and profiling platform — the backbone of a whole digital ecosystem of sites and apps.
5M+ user accounts & daily logins served
Two brands, one coherent experience
Directed the digital brand merge across every group touchpoint — later cited as a Deutsche Telekom group case study.
Web-touchpoint satisfaction to an all-time-high 94%
Payments people actually complete
Redesigned online invoice payment and e-billing services that lifted satisfaction and recovered revenue.
90% satisfaction · 40% fewer overdue payments
Recognized expertise
Accessibility, from someone who wrote the book on it.
Matthaios is the author of Web and Mobile Accessibility: A Comprehensive Guide to WCAG 2.2, the ADA, and the European Accessibility Act (Second Edition) — a practical guide covering Section 508 and EN 301 549 alongside the core standards — and writes on the evolving UX landscape for UX Planet, Fast Company and The Decision Lab.
With the European Accessibility Act now in force, inclusive design is no longer optional. UXellence brings author-level depth to accessibility — turning compliance from a risk into a competitive advantage, and making sure the products you ship work for everyone.
More on Matthaios's background →Understand
Discover the business context and what users actually need.
Define
Frame the problem, architecture and success metrics.
Design
Wireframe, prototype and validate with real users.
Deliver
Ship production-ready design and a system that scales.
How it works
One continuous thread, from research to delivery.
Because one senior expert carries the work end to end, nothing is lost in translation. You get momentum, clarity, and decisions grounded in evidence rather than opinion.
- Senior practitioner on your project — never juniors on your budget
- Evidence over opinion: every decision grounded in research
- Accessibility built in from day one, not bolted on at the end
- Clear, prioritized recommendations your team can act on
- For larger programs, a trusted network of specialists — always senior-led by Matthaios
Capabilities
Depth across the whole discipline
UX/UI Design
Information Architecture
Accessibility Consultation
Usability Testing
UX Research
User-Centric Design Strategy
Interaction Design
Wireframing & Prototyping
User Testing & Feedback Analysis
Trend Analysis & Forecasting
FAQ
Frequently asked questions
What is UXellence?
UXellence is the UX consultancy of Matthaios Mantzios, a UX design leader with 18+ years of experience. It provides full-lifecycle UX services — strategy, research, UX/UI design, information architecture, design systems and accessibility — for organizations that need senior expertise across the entire product lifecycle.
What UX services does UXellence offer?
UXellence offers UX strategy and design leadership, user research and usability testing, UX/UI design, information architecture, design systems, accessibility consulting (WCAG and European Accessibility Act readiness), and UX audits.
Who is Matthaios Mantzios?
Matthaios Mantzios is the founder of UXellence and a UX design leader with over 18 years of experience across telecom, publishing, public sector and media. He is Nielsen Norman Group (NN/g) UX certified, a Certified Scrum Product Owner, and the author of Web and Mobile Accessibility: A Comprehensive Guide to WCAG 2.2, the ADA, and the European Accessibility Act (2nd edition).
Does UXellence help with the European Accessibility Act (EAA)?
Yes. UXellence provides WCAG audits and European Accessibility Act readiness roadmaps, led by the author of a comprehensive accessibility guide — including barrier identification, remediation planning and team training.
How do I find out where we stand?
Three ways, by how much certainty you need. The free EAA & WCAG readiness checklist is a 10-minute self-assessment. The EAA Exposure Report is a fixed-scope assessment of ten screens in five working days. A full audit covers the whole product. The Report's fee comes off the audit if you go on to book one.
Where is UXellence based?
UXellence is based in Athens, Greece, and works with clients internationally on a remote-first basis.
How do I start a project with UXellence?
Contact UXellence at matthaios@uxellence.gr or through the contact form. Most engagements begin with a short discovery call to scope the right first step — often a UX audit or a focused research sprint.
Work with a senior UX partner, from first insight to launch.
Tell us about your product and the problem you're solving. You'll get a candid view of where senior UX moves the needle — and where it doesn't.
Start a project