Freelance / contract missions, fully remote. Best fit: scale-up SaaS, AI / LLM, fintech or deeptech teams that need a senior frontend engineer to take over a React / Next.js codebase, ship a product V1, build a design system or migrate a legacy front end to React. Also scientific UI, marketplaces, back-offices. Formats: 48h audit, 10-day sprint, multi-month contract.
Looking for a job
Timon Prata
@timonprata
Freelance Senior Frontend Engineer, 8+ years. I take over live React / Next.js codebases and deliver visibly in week one. AI, SaaS, scientific UI.
FranceWhat I'm looking for
Freelance senior frontend engineer with 8+ years of experience, and member of Cantem, a collective of senior independent developers from École 42. I build React, Next.js and TypeScript product interfaces for complex domains: AI and LLM products, legaltech, scientific software, SaaS and Web3.
My strength is codebase takeover: I onboard on a live React / Next.js codebase, map the technical debt, ship a first mergeable quick win within the first days and deliver visible results in week one. I structure frontend architecture, build design systems, turn Figma designs into shippable UI, and keep quality high with tests, CI/CD, monitoring, WCAG 2.2 accessibility and Core Web Vitals.
Selected work: lead frontend at JIMINI AI on a cloud-native LLM platform for legal professionals (about 10K production requests per day; AI chat, embeddings-based document analysis, Auth0 multi-role access). For a scientific R&D software company, I designed and built the interface technicians use to draw molecular structures. For a wedding-planning SaaS, I shipped the V1: dashboard, signup, RSVP, guest management, budget and payment flows. Earlier, I integrated Solana wallets and NFT mechanics into a React Native app at Octo Gaming, and led the Twig/PHP to React migration of a high-traffic casino back-office.
French native, fluent English (international missions, documentation, pair programming). Fully remote, freelance or contract.
Experience
Work history, roles, and key accomplishments
SC
Senior Frontend Engineer, Product UI
Scientific R&D software company
Apr 2025 - May 2026 (1 year 1 month)
Designed and built the product interface technicians use to draw molecular structures. Built UI workflows for a demanding scientific context (clarity, precision, productivity) and translated complex domain logic into an interface non-developer users rely on every day.
WS
Frontend & Product Engineer
Wedding planning SaaS startup
Feb 2026 - Apr 2026 (2 months)
Shipped the V1 of a wedding-planning SaaS: dashboard, signup, RSVP, guest management and budget. Built the product UI, forms and responsive flows for couples and vendors, and integrated the payment flows of the shared gift fund into the interface.
JA
Lead Frontend Developer
Jimini AI
Jul 2023 - May 2025 (1 year 10 months)
Led the frontend of a cloud-native LLM platform for legal professionals, in production at about 10K requests per day. Built the AI chat and embeddings-based document analysis, integrated Auth0 with a multi-role architecture and real-time WebSockets, and automated critical workflows (CronJobs, GitHub Actions CI/CD). Worked directly with product and design on a fast, accessible frontend.
TF
Lead Frontend Developer
The Luck Factory
Jan 2023 - Jun 2023 (5 months)
Led the migration of a high-traffic online casino back-office from Twig/PHP to a React architecture, integrated the new frontend into a microservices ecosystem through REST APIs, and added unit and functional tests with Jest and React Testing Library.
OG
Lead Frontend Developer
Octo Gaming
Aug 2022 - Jan 2023 (5 months)
Integrated Solana wallets and NFT mechanics into the React Native mobile app of a gaming / Web3 product, and supported the app's blockchain transition and the OTK token launch. Shipped gameplay features and UX improvements, maintained the high-traffic SEO landing page for the launch, and fixed critical cross-platform bugs during activity peaks.
LD
Fullstack JS Developer, Web & Mobile
Le Big Day
Jul 2021 - Jun 2022 (11 months)
Took over an incomplete legacy codebase and turned it into a web and mobile app for personalized photo products and subscription boxes. Redesigned the whole interface and user flows (dynamic product builder, animated photo books, time-limited events), built the React Native app (real-time chat, push notifications, native camera) and integrated Stripe recurring subscriptions and promo codes.
WT
Frontend Integrator, React Developer
Wizard Technology
Jan 2020 - May 2021 (1 year 4 months)
Full React rebuild of the Sodexo front end: responsive, cross-browser and WCAG-compliant. Built pixel-perfect UI components aligned with Sodexo's new design system and multilingual layouts with integrated translations, using reusable components to speed up integration.
Education
Degrees, certifications, and relevant coursework
École 42
Master's-equivalent curriculum, Computer Science
Master's-equivalent software engineering curriculum at École 42, Paris: project-based, peer-to-peer learning.
Availability
Looking for a job
Location
FranceAuthorized to work in
Salary expectations
100k+ EUR
Social media
Job categories
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