Simple solutions
I like being challenged, and I like finding the simplest solution to a problem.
Availability: Currently at Keolis Group
Frontend Developer · Web Accessibility & Performance
I work on accessibility and frontend at Keolis, remotely from Barcelona. Before that I spent almost four years at Decathlon, building storefronts with Svelte.
About me
Hi, I'm Kévin Sauvage
Current role: Currently at Keolis Group (remote)
I'm a frontend developer in Barcelona, working mostly with React, Next.js, Svelte and TypeScript.
I got into this during the 2020 lockdown. I was bored, so I spent the time learning to code, then did the Le Wagon bootcamp and got my first developer job in 2021. Before that I spent seven years in very different jobs: customer service at Avis, managing a small business, and the front desk at Soho House.
At Keolis I started as the accessibility specialist and only developer on ilévia, a French public transit platform. RGAA compliance went from 30% to 84%, and I added accessibility checks to CI so problems get caught earlier. Now that's in place, my work has become more general frontend development.
Before Keolis I spent almost four years at Decathlon, where I built a Svelte component library used by storefronts in more than 15 countries and worked on page speed for the Spanish site.
What I enjoy most is a difficult problem with a simple solution, and keeping a codebase clean.
Languages
- FrenchNative
- EnglishC1 Certified — English credential (opens in a new tab)
- SpanishFluent
What I care about
A clean codebase
I care about keeping a codebase clean. It makes the next change easier, for me and for whoever comes after me.
Working with people
I work best with others. I like teams where people share what they know and give each other honest feedback.
Career
Professional Journey
Where I've worked and what I did there, from component libraries to performance and accessibility.
Keolis Group
Frontend Developer
Feb 2026 – PresentStarted as the accessibility specialist and only developer on ilévia, a French public transit platform.
Took RGAA compliance from 30% to 84% by reworking core UI components: semantic HTML, ARIA, keyboard navigation and screen reader support.
Added Jest-axe and Cypress-axe to CI so accessibility problems get caught before release.
Made ESLint (jsx-a11y and custom rules) a required check on pull requests.
Worked with product and design so accessibility is considered from the wireframe stage.
Now working on frontend development more broadly.
Next.jsReactTypeScriptTailwindJest-axeCypress-axeESLintjsx-a11yARIASemantic HTMLAccessibility
Decathlon Core
Frontend Developer
Oct 2023 – Dec 2025Built a Svelte component library used by storefronts in 15+ countries.
Moved the checkout out of a monorepo into a versioned npm package (Lerna), with Strapi feature flags and per-country configuration.
Ran A/B tests on conversion and adoption across international markets.
Worked with designers in Figma and Storybook to ship accessible, well-tested components.
Owned the test suite (Jest, Cypress) and increased coverage.
SvelteJavaScriptStorybookJestCypressFigmaTailwindAccessibility
Decathlon Spain
Frontend Developer
May 2022 – Oct 2023Improved Core Web Vitals on the Spanish storefront: average load time down 1.5s, higher Lighthouse scores.
Built a modular Svelte component system that cut duplication and sped up new product features.
Rolled out WCAG 2.1 across the storefront.
Wrote the team's documentation standards for components and technical decisions.
SvelteJavaScriptCore Web VitalsTailwindPerformanceAccessibility
Subforce
Frontend Developer
Jun 2021 – May 2022Built full-stack features in React, Next.js, Node.js and Express.js, including third-party API integrations.
Designed state management with Redux and Context API for complex UIs.
Moved a legacy JavaScript codebase to ES6+, which cut bugs and made it easier to maintain.
ReactNext.jsReduxNode.jsExpress.jsMongoDBJavaScriptSass
Testimonials
What Colleagues Say
A few words from colleagues and managers I have had the chance to work with.
01 / 03
"From day one, he showed a rare ability to take on the most complex technical challenges and find pragmatic solutions. His ability to adapt quickly, understand the bigger picture, and deliver impact made him an invaluable asset in both contexts. I would gladly work with Kevin again — any organization would be lucky to have him."
Portfolio
Featured Projects
Some things I've built outside my day job.
Design & development (solo) · 2026
ORUVA — Jewelry E-Commerce
ORUVA is a live European jewelry label selling everyday rings, necklaces, earrings and bracelets to shoppers in Spain and France. I designed and built the whole storefront on Next.js 16 and Shopify: a three-language catalog, persistent cart, customer accounts, wishlist and predictive search, with content managed in Shopify rather than in code.
Live demo in English, Spanish and French
Brand copy, menus, policies and page content editable in Shopify, no redeploy needed
Storefront + Admin APIs typed end-to-end with GraphQL Code Generator
Automated accessibility (axe, WCAG 2.1 AA) and add-to-cart smoke tests in Playwright
Next.js 16React 19TypeScriptShopify Storefront APIShopify Customer Account APIShopify Admin APIGraphQLGraphQL Code Generatornext-intlTailwind CSS 4Radix UIshadcn/uiServer ActionsZodUpstash RedisPlaywrightVercel
Design & development · 2026
ComplyLoop — Accessibility Compliance
ComplyLoop checks React and Next.js codebases for accessibility against RGAA 4 and WCAG 2.2. It scans the source, optionally audits the running site, opens fixes as draft pull requests, and keeps an evidence log of every step. It is aimed at French agencies that deliver RGAA-regulated sites for several clients.
Source scan (AST checks and jsx-a11y) plus runtime audits with Playwright and axe
A finding only closes once a re-run confirms the fix; AI never sets a status
Append-only evidence log, exportable as JSON, Markdown or HTML
Public repository, with CI, unit tests and Playwright end-to-end specs
Next.js 16React 19TypeScriptPostgresDrizzle ORMAuth.jsGitHub App (Octokit)GitHub ActionsPlaywrightaxe-coreVercel AI SDKZodTailwind CSS 4VitestSentry
Credentials
Continuous Learning
A few courses and certificates, plus what I am learning at the moment.
Deepening Web Accessibility
Self-directed · In Progress
Learning more about WCAG 2.2, ARIA authoring practices and screen reader testing, and using it in my work at Keolis.
WCAG 2.2ARIAScreen Readers
C1 English Certificate
EF SET
Official C1 Advanced English certification for professional communication in international environments.
C1 Advanced EnglishInternational Collaboration
View CredentialReact: Using TypeScript
LinkedIn Learning
Course on building type-safe React applications with TypeScript — props, hooks, and patterns for complex front-ends.
ReactTypeScriptType Safety
View CredentialJavaScript: The Advanced Concepts
Udemy
Advanced JavaScript course covering closures, prototypes, async programming, and modern ES6+ features for complex applications.
Closures & PrototypesAsync PatternsES6+
View CredentialFull-Stack Web Developer Bootcamp
Le Wagon
Where I started: 9-week intensive bootcamp covering Ruby on Rails and JavaScript. Since then, 5+ years of production React, Svelte, and Next.js work.
Full-Stack FoundationsRuby on RailsJavaScript
View CredentialFAQ
Questions, Answered
The things people usually ask before getting in touch — answered upfront so you don’t have to.
I'm currently a frontend developer at Keolis Group, working remotely from Barcelona, and I'm happy to chat. The fastest way to reach me is the contact form or email below; I reply within 24 hours on weekdays.
My day-to-day focus is my full-time role at Keolis, so I only consider small, well-scoped collaborations — audits, code reviews, or mentoring. Tell me what you have in mind and I'll give you a straight answer.
React, Next.js, Svelte, and TypeScript, with Tailwind CSS, Storybook, and testing built on Jest, Cypress, and axe. My specialties are web accessibility, design systems, and Core Web Vitals performance.
Yes. Decathlon and Keolis work is proprietary, but I can walk through NDA-friendly summaries: architecture decisions, metrics like the −1.5s LCP improvement, and lessons learned. Just ask.
Barcelona, Spain (CET, UTC+1), working remotely. I work in French (native), English (C1, EF SET), and Spanish (fluent) — comfortable in multicultural, distributed teams.
Contact
Let's connect
Based in Barcelona, working remotely at Keolis Group. Feel free to get in touch.
Barcelona, Spain — CET (UTC+1) · English, French, Spanish