Freelancer profile translated to English.
Back to original languageAbout Guillaume
I've seen digital products slow down because no one documented why. Why this stack. Why this convention. Why this component existed next to another almost identical one.
When a multi-product scale-up accelerates, complexity creeps in unnoticed: duplication, scattered UI decisions, dependency on 1-2 key people. The code runs, but consistency walks out with those who maintained it.
I step in as a Transition Lead Frontend to structure what's not yet visible: explicit conventions, ADR (Architecture Decision Records), governance, knowledge transfer on Design Systems when it's the main concern, or across the entire frontend scope when it's broader.
My goal: for your team to be able to run the system without me in 6 months.
Currently at Boiron Digital (Lead Front multi-projects).
Previously: ENGIE (Design System), Rubix (Design System + e-commerce redesign), ENER-PACTE, Lelivrescolaire, and 10+ teams supported on React, Next.js, Web Components.
Objective: transform the frontend into an accelerator, not a constraint.
"Certified Masterclass for Tech Leads (The Principal Dev) on Technical Leadership, Team Topologies, Continuous Delivery."
French
Native or bilingual
English
Fluent
Chinese
Basic
Can work on-site
Lyon (up to 50km), Paris (up to 50km), Toulouse (up to 50km), Lille (up to 50km), Nantes (up to 50km)
Experience
- BoironLead Frontend Transition (multi-projects)PHARMACEUTICALS INDUSTRYMarch 2026 - Today (3 months)Lyon, France90-day Lead Frontend transition mission, prior to a permanent hire.The scope covers several Boiron digital products (Product Sites, Professional Portal, CEDH-CDFH-HC business applications, winter/seasonal content projects). My role: technically lead the transition, stabilize architectural choices, structure governance, and prepare for handover to the future permanent Lead.Current work:- Frontend maturity audit and multi-project technical mapping- ADR (Architecture Decision Records) for structuring decisions- Cross-project conventions coordination (DoR/DoD, MR-process)- Migration from Prismic CMS to Payload on certain products- Handover document for permanent LeadStack: React · Next.js · TypeScript · Tailwind · Turbopack · Storybook · Payload CMS
- engieReact Lead on the Cross-Functional Design SystemENERGY AND UTILITIESFebruary 2024 - March 2026 (2 years and 1 month)Paris, FranceContextLarge energy group (~95,000 employees). 2-year mission (Feb 2024 - Mar 2026). Goal: unify 50+ group digital applications on a cross-functional Design System covering React, Angular, and Web Components.Missions & Impacts
- React Lead within the Design System team (5-7 people: 3 devs + designers + PM).
- 10+ cross-functional components delivered over time — buttons, modals, forms, navigation.
- 10+ consuming teams supported in adopting the DS.
- Implementation of Playwright visual tests in CI → 20-25% reduction in UI bugs in production.
- Figma Code Connect integration: mockups push to code, reduced friction between designers/devs.
- Systematic ADRs for structuring choices (variants, tokens, accessibility, naming).
StackReact - Angular - Web Components - TypeScript - SCSS - Storybook - Playwright - Figma Code Connect - GitHub Actions - ADR - codeblendFounderJanuary 2024 - Today (2 years and 5 months)Lyon, FranceCodeblend is my freelance frontend business. I conduct my missions through this EURL, allowing me to build sustainable client relationships (framework agreements, multi-year follow-up, ADR, methodology).Specialty: Transition Lead Frontend for scale-ups — multi-project, technical governance, knowledge transfer.
Recommendations
+7
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Education
- Computer Science Diploma (DUT)IUT A Informatique La Doua Lyon2004Formation axée sur le développement logiciel, l’algorithmique et l’architecture applicative. Projets en équipe simulant des environnements réels : gestion de bases de données, conception UML, programmation orientée objet (Java, C), administration de systèmes UNIX, travail en réseau. Préparation directe aux contextes projets et aux missions techniques.