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Raphaël BadiaRB

Raphaël Badia

Supermalter

Next.js | React.js | AI Frontend Developer

€550/day
7 projects
Paris, FR
8-15 years

Average response time: 1 hour

Freelancer profile translated to English.
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About Raphaël

Is your frontend team **no longer moving forward**, every release **breaks something**, and it's gotten worse since they started using **AI**?

A poorly performing team has a process problem, not a talent problem. I intervene on yourReact.js / Next.jscodebases tostabilizewhat's breaking,accelerateyour releases, and prepare your product to **scale**.

Here are the concrete results achieved for my clients:

  • Maiia (React.js / Next.js): creation from scratch of the platform and design system in atomic design (80+ components), migration of 70,000 healthcare professionals without interruption. Platform scaled from500,000 to 3.25 million usersduring COVID-19 vaccination.
  • Billiv (React.js / Next.js): monorepo architecture with unified design system across 4 applications ->40% code deduplicationand app stabilization (0 production regressions) thanks to my **Cypress e2e tests**.
  • Noticia (React.js / Next.js): full-stack monorepo architecture,4 web products delivered in 2 months(webapp, dashboard, admin) ->raised €500k in funding

You integrate me into your team and I amimmediately operational**: I develop your features in **React.js / Next.jswhile structuring what needs to be done —design system**, **unit tests, integration tests, and E2E tests(Jest, Cypress, Playwright), **monorepo architecture**, **CI/CD**, DX. You gain a developer who delivers AND continuously improves the codebase.

Furthermore, your team gains skills with me: **Next.js coaching**, code reviews, implementation of **good testing practices**.

I work withstartupsandscale-upsthat have found their market but whose codebase is starting to **hinder growth**.

My typical missions: audit of a tired codebase, senior frontend developer reinforcement, design system architecture, monorepo implementation, robust E2E tests.

Have a project in mind? Write to me!
  • English

    Fluent

  • French

    Native or bilingual

Remote only
Primarily works remotely

Experience

  • Groupe Barrière
    Frontend Developer React.js | Next.js | Typescript | Design System | AI
    ENTERTAINMENT AND LEISURE
    April 2026 - Today (4 months)
    Paris 08 Élysée, France
    → Mission Objective: Overhaul the "Account" section of Groupe Barrière (user account and loyalty program management) by modernizing the UX/UI and establishing solid foundations for a scalabledesign systemand frontends using React.js & Next.js.

    → Achievements:
    • In-depth audit of the existing design system: analysis of UI inconsistencies, industrialization limitations, and UX impacts, with concrete recommendations for a scalable overhaul across the Barrière ecosystem.
    • Redesign of the Account section (user account, loyalty, benefits) in React / Next.js, leveraging design system principles to improve UI consistency, user flow fluidity, and perceived quality.
    • Implementation of unit and non-regression tests with Jest to secure UI components, ensure reliable evolution, and guarantee the stability of critical account and loyalty-related user journeys.

    → Technical Stack: React.js · Next.js · Jest · Design System (audit & structuring) · Playwright · Storyblok (headless CMS for content contribution by marketing) · Storybook
    React.js Next.js Design System Jest Typescript
  • Billiv
    Frontend Developer React.js | Next.js | Typescript | E2E Tests | Design System | AI
    SOFTWARE PUBLISHING
    December 2022 - June 2024 (1 year and 6 months)
    Paris, France
    → Mission Objective: Overhaul the frontend architecture of a omnichannel SaaS platform to accelerate releases, ensure reliable deployments, and harmonize the product experience across 4 React.js / Next.js applications.

    → Achievements:
    • Migration of 4 applications to a Turborepo monorepo with GitHub Actions CI/CD and a feature branch system, reducing time-to-release to less than 1 week and improving development velocity by +30%.
    • Design of a shared design system with shadcn/ui, Tailwind CSS, and Storybook, enhancing UI/UX consistency, perceived quality, and frontend maintainability across all SaaS products.
    • Implementation of Cypress e2e tests, Jest / Testing Library integration tests, and strict ESLint / Prettier rules, reducing production bugs by 50% while maintaining an NPS > 70.

    → Technical Stack:
    Next.js · React.js · TypeScript · Turborepo · shadcn/ui · Tailwind CSS · Storybook · Cypress · Jest · Testing Library · GitHub Actions · ESLint · Prettier
    Next.js Typescript Cypress React.js End-to-End Testing (E2E)
  • Maiia
    Frontend Developer React.js | Next.js | Typescript | E2E Tests | Design System | AI
    MEDICAL
    April 2019 - July 2022 (3 years and 3 months)
    Paris, France
    → Mission Objective: Overhaul a startup's appointment booking and teleconsultation platform, then ensure its scaling during the COVID crisis with a robust, high-performance, and uninterrupted frontend service.

    → Achievements:
    • Design of a design system in Atomic Design (80+ React components documented via Storybook) to accelerate development, standardize UX, and improve perceived quality.
    • 0-downtime migration of 70,000 healthcare professionals to React / Next.js, with Core Web Vitals optimization, technical SEO, and scalable architecture to handle 6x load without critical incidents.
    • Development of critical features: B2B white-label appointment booking, COVID vaccination waiting list, Vitale card scanning, health insurance integration, advanced search, and Cypress E2E testing strategy ensuring 0 production regressions.

    → Technical Stack: React.js · Next.js · TypeScript · Redux · React Query · Storybook · Cypress · Material UI · react-hook-form · SEO
    React.js Next.js Cypress Typescript React Query

Reviews

5.0

Out of 5 ratings

F

Frédéric

youzd

Reviewed on 6/12/2024

We hired Raphaël to coach our dev team in their first steps with the next.js framework. Beyond his technical expertise which allowed us to avoid bad choices in the implementation of our first features, Raphaël showed skill and pedagogy in getting our teams to adopt good development practices with the next.js framework (especially testing). Calm, didactic, able to quickly grasp our team's challenges and constraints, Raphaël perfectly fulfilled his coaching role during this first mission, which we renewed.
AD

Account deleted

Reviewed on 4/24/2019

Raphaël did a great job on our React Native architecture (for a new application). Very efficient, he delivered professional work! We recommend him!

Recommendations

Maxime CampaneMC
Tristan DardoizeTD
Amélie P.AP
+1
Maxime Campane and 3 other people have recommended Raphaël

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Education

  • DIGITAL TECHNOLOGY ARCHITECT
    42
    La pédagogie unique de l'école 42 m'a permis d'apprendre à faire face à n'importe quelle situation ou problème de façon calme et autonome. J'y ai également appris à travailler en équipe, à faire de la veille technologique et à communiquer efficacement avec des clients.

Certifications

  • TDD & Clean Architecture in the Web world with React/Typescript/Redux
    Wealcome
    2025
    Clean Architecture

Skill set

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