Freelancer profile translated to English.
Back to original languageAbout Justin
Frontend developer and technical lead with over 7 years of experience, I support companies in the design and structuring of complex web applications, with a specialization in design systems and modern frontend architectures.
I position myself as a **hands-on frontend lead**, with cross-functional expertise: Angular, React, TypeScript, StencilJS, as well as the fundamentals of HTML/CSS. This versatility allows me to design robust, interoperable solutions adapted to various technical contexts.
I work on the structuring aspects of projects: architecture definition, monorepo setup (Nx, PNPM, Turborepo), technical choices, design system conception, CI/CD pipelines (GitHub Actions), and release strategies.
I also support teams: mentoring, onboarding, recruitment, and dissemination of best practices.
In parallel, I host live development sessions to popularize advanced frontend architecture concepts, and I offer Angular and TypeScript training.
Achievements:
- 3 complex Angular web applications (energy, telecom, agri-food)
- ENGIE group Design System (maintenance and evolution)
- Development and delivery of a critical Next.js portal in 1 month
- Migration from Objective-C to Swift (SFR mail app)
- Setup of CI/CD and AWS infrastructures
- Development of AI agents to accelerate workflows
I am looking forlong-term assignmentsrelated to design systems, frontend architecture, redesigns, or build from scratch projects.
French
Native or bilingual
English
Fluent
Can work on-site
Lyon (up to 20km)
Experience
- ENGIETechnical Referent Design SystemENERGY AND UTILITIESSeptember 2023 - Today (2 years and 9 months)Paris, FranceWithin the ENGIE group, I act as the frontend technical referent for the design system used by nearly 200 internal projects.Initially integrated as an Angular expert, I quickly took on the role of technical lead following the departure of the previous manager. I now steer all technical decisions for the design system, in collaboration with a team composed of senior developers, a designer, and a PO.I design, evolve, and stabilize an ecosystem of multi-framework libraries (Angular, React, TypeScript, Web Components via StencilJS) to ensure consistency, performance, and accessibility across the group.I have also led several structuring initiatives:
- Monorepo migration (Lerna → PNPM + Turborepo)
- Stack evolution (Angular 16 → 20, React 18 → 19)
- Complete setup of CI/CD pipelines via GitHub Actions
- Structuring of releases with Changesets
- Industrialization of builds (Vite, Rollup, TSUP)
- Deployment of AWS infrastructure
In parallel, I develop cross-functional tools to improve the adoption and usage of the design system, including:- An automated analysis tool for library usage
- A Next.js web portal (connected to a headless CMS), designed and delivered in 1 month, which has become a central knowledge base for the group's technical teams
- AI agents to optimize development workflows
My role also includes a strong cross-functional and leadership dimension:- Technical decision-making and architecture scoping
- Recruitment and onboarding
- Code reviews and developer support
- Community management around the design system
- Technical presentations and popularization (FR/EN)
- Close collaboration with UX/UI, architects, DevOps, and product teams
I pay particular attention to accessibility and component quality to offer robust, inclusive, and sustainable standards. - Enedis - LyonAngular LeadENERGY AND UTILITIESOctober 2022 - August 2023 (10 months)Lyon, FranceDesign and development of a web application for monitoring all of Enedis's electric vehicle charging stations.Tasks:- Design and implementation of the application's front-end architecture (monorepo)- Design and development of new features- Integration and testing of mockups produced by the design team- Creation of a project design system- Technical debt management- Mentoring junior developers- Assisting business stakeholders with requirements gatheringContribution:- Complete autonomy in front-end architecture design. Proven effectiveness on multiple occasions (separation of concerns, flexibility to changes, rapid skill development for new developers, ...)- Angular referent role within Enedis. Consulted to assist projects in designing complex features, qualifying profiles, ...- Management of a changing business environment
- ORANGEExperienced Angular DeveloperTELECOMMUNICATIONSMarch 2021 - October 2022 (1 year and 7 months)Lyon, FranceDevelopment of a WEB portal in Angular communicating via GraphQL to its Back for Front in NestJS.My mission:- Development of Back-end features (NestJS)- Development of Front-end features (Angular)- Front-end integration (internal CSS framework)- Architecture design- Interfacing with process APIs (guided process application)- Working in a multi-team SCRUM environment- Assisting the Scrum Master in optimizing processes and tools
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Education
- Computer Science EngineerINSA De Lyon2019Etude d'ingénierie : gestion de projet, paradigmes de programmation, développement fullstack, intelligeance artificielle.