Freelancer profile translated to English.
Back to original languageAbout Jacky
Senior Frontend React Lead - 8+ years, rated 5/5 ⭐
I deliver React interfaces that hold up in production, whether it's leading from scratch, reinforcing your team as a senior, or on a fixed-price basis.
240,000+ users on La Poste's GenAI assistant. Front-end from scratch for France's first sovereign Datahub at Cleyrop. Stabilized the Obat SaaS in 3 months by reinforcing the team. React, TypeScript, Next.js, in production, at scale.
⚡ What I deliver concretely
- Tested, documented, maintainable code (coverage > 80%, Jest + RTL)
- A design system that survives redesigns (tokens, Storybook, accessibility).
- Measurable performance: LCP, bundle size, audited React rendering.
- A stack that ages well, yours or one we choose together.
🔑 Key Experiences
- 📮 LaPoste - Frontend Lead, internal GenAI assistant (240,000+ users). Chat x LLM, complete design system, React / TS / Zustand / TailwindCSS, Jest + RTL.
- 🌐 Cleyrop - France's 1st sovereign Datahub, front-end from scratch. React / TS / Next.js, LLM for data analysis, advanced visualizations, GDPR.
- 🛠️ Obat - B2B SaaS for tradespeople, reinforcing the team. Legacy JS → React migration, restored performance, solid tests.
🤝 How we can collaborate
- Frontend Lead (new project or takeover): scoping, stack, initial components, knowledge transfer to the team.
- Senior React Expert reinforcement: I integrate into your codebase, review, pair, deliver features.
- Fixed-price: scope and deadline agreed upon together, committed delivery.
🎯 My Differentiators
- Solid experience in frontend interfaces x LLM: chat, RAG, agents, AI-driven UX.
- Augmented by AI (Claude, Codex, Cursor): up-to-date on the best tools to deliver quickly and cleanly.
- Cheerful, direct, "contagious enthusiasm" (according to my Malt clients)
- Professional English.
📩 Have a project or a need in mind? Tell me the context, and I'll respond within the hour!
French
Native or bilingual
English
Fluent
Can work on-site
Paris (up to 50km)
Experience
- DocaposteLead Frontend React DeveloperPUBLIC SECTORNovember 2024 - May 2026 (1 year and 6 months)Paris, France
La Poste Internal GenAI Conversational Assistant - 240,000+ users in scope.
Mission:Allow La Poste group employees (Banque Postale, BGPN, etc.) to instantly access internal business data via a chat connected to LLMs and linked to proprietary document databases.Role:Frontend Lead for V1 - from the first component to production.🛠️ WHAT I DELIVERED- Modular, end-to-end typed frontend architecture, designed to last.
- Chat x LLM interface with RAG on internal databases (augmented search, citations, streaming).
- Complete design system (tokens, components, Storybook) — reusable by other product teams in the group.
- Enterprise authentication via Azure MSAL (SSO).
- Integration tests Jest + React Testing Library, coverage > 80%.
- Continuous delivery on an evolving functional scope, with upstream scoping of technical choices.
📈 WHAT IT PRODUCED- Production deployment of V1 for the scope of 240,000+ internal users.
- Information access time reduced from "I search in 3 tools" to "I ask."
- Codebase taken over frictionlessly by internal teams after delivery — zero technical debt reported at handover.
⚙️ Stack: React · Nextjs · TypeScript · Zustand · TailwindCSS · Azure MSAL · Jest + RTL · LLM (RAG on internal corpus) · Storybook · - ObatFrontend React DeveloperSOFTWARE PUBLISHINGJuly 2024 - November 2024 (3 months)Paris, France
SaaS for managing tradespeople (quotes, invoices, project tracking) - B2B platform in production, established product team.
Role:Senior React Expert, reinforcing the existing team.Mission:Stabilize a scope riddled with legacy debt (vanilla JavaScript) and restore product velocity.🛠️ WHAT I DELIVERED- Progressive migration from vanilla JS legacy to React, without freezing the product roadmap (features continue to be released during the migration).
- Critical bug fixes reported by users — mobile tradespeople, zero tolerance for UX friction.
- Audited and optimized React rendering: targeted memoization, bundle splitting, re-renders tracked on hot pages.
- Development of product features in parallel, in pairs with the Product Manager.
- Solid test base (React Testing Library) on high-churn areas — regressions eliminated, deployments are now serene again.
- Modular refactoring: code that a junior developer can take over without a briefing.
📈 WHAT IT PRODUCED- Critical scope stabilized in ~3 months.
- Predictable delivery pace restored: end of "legacy unforeseen issues" that ate up every sprint.
- Product team can plan without a permanent backup budget.
⚙️ Stack: React · Next · TypeScript · JavaScript (legacy) · React Testing Library · progressive migrationMission Format:Senior React Expert reinforcing an existing team — I integrate, I deliver, the team gains autonomy. - CleyropFrontend React DeveloperTECHJune 2021 - April 2024 (2 years and 10 months)Paris, France
France's 1st sovereign Datahub — end-to-end data lifecycle management platform: collection, storage, governance, processing, exploitation, visualization.
Role:Senior Frontend React Developer. Joined at the project's inception — front-end from scratch, participation in establishing patterns and foundations for the frontend stack.Challenge:Make a platform that handles massive volumes of sovereign data usable by business users (without SQL, without data expertise), under strict GDPR constraints and public sector/large account specifications.🛠️ WHAT I DELIVERED- Contribution to the from-scratch frontend foundation: stack, structure, design system, coding conventions.
- UX designed for non-technical business users: data exploration via point-and-click, LLM-assisted querying.
- Integration of LLMs for automatic analysis of large volumes (summaries, classification, detection, natural language queries).
- Data catalog: advanced search, metadata management, role-based access control.
- Visualization modules: dashboards, interactive charts, drill-downs, free exploration.
- GDPR by design security: encryption, audit trail, consent management, native sovereignty.
📈 WHAT IT PRODUCED- Platform deployed in production.
- Adoption by major public and private organizations for their critical data.
- Cleyrop recognized as a French leader in sovereign data — a credible alternative to US hyperscalers.
⚙️ Stack: React · TypeScript · Next.js · data-viz · LLM · GDPR by design
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Education
- Master Computer Science, Ingénierie informatique422021Computer Science, Ingénierie informatique, React.js, Typescript, C, React
- Mathematics for Machine Learning, MathématiquesImperial College London2020Mathematics for Machine Learning, Mathématiques
Certifications
- Mathematics for Machine Learning: Multivariate CalculusCoursera2020
- Mathematics for Machine Learning: PCACoursera2020