Freelancer profile translated to English.
Back to original languageAbout Sébastien
For over 6 years, I have been supporting startups, SMEs, and local authorities in the design and development of custom mobile applications and platforms.
I get involved from the very first project reflections: defining functionalities, technical architecture, frontend and backend development, all the way to production.
Today, I also integrate artificial intelligence into the products I develop to create truly useful features: assistants, automation, intelligent search, content generation, or data analysis.
What I can help you achieve:
- Design a product from an idea
- Develop an iOS & Android application
- Create the backend and APIs
- Modernize an existing application
- Add AI-based features
- Design a dashboard or back-office
- Train your teams on AI tools and development technologies
My way of working:
I like to understand my clients' business before writing the first line of code.
My goal is not just to develop a feature, but to build a coherent, scalable, and user-friendly product.
This approach has led me to work with startups, agencies, local authorities, and sports federations.
Technologies:
React Native • Expo • TypeScript • React • Node.js • NestJS • Supabase • Firebase • MongoDB • OpenAI • Claude • Git • CI/CD
Availability:
Available for remote work anywhere in France.
So, if you have an app idea, a product to evolve, or want to integrate AI into your business? Let's discuss your project.
French
Native or bilingual
English
Fluent
Can work on-site
Nancy (up to 20km)
Experience
- Godare servicesLead Fullstack Developer | Creation of an exchange platform (mobile, web, and back-office)IMPORT AND EXPORTAugust 2025 - April 2026 (8 months)Complete development of the Swap Direct platform, an exchange application, from design to production.Carried out the application design, mobile development, web application, and administration back-office.Implemented a complete architecture with a React Native mobile application, a Next.js web application, and a back-office for managing users, content, and the platform.Developed the backend, APIs, database, authentication, and core platform functionalities.Project completed autonomously, from the initial idea to the final product.
- URBSFullstack Designer & Developer | Business application for local authorities (React Native, Node.js)PUBLIC SECTORMarch 2023 - Today (3 years and 4 months)Nancy, FranceDesign and development of the URBS application for territorial authorities.Involved in the entire project: defining features, designing the user interface and experience, technical architecture, and platform development.Developed a React Native mobile application, a web application, and an administration back-office.Developed the backend and APIs using Node.js with a MongoDB database.Implemented specific business features for local authorities: user management, data management, internal tools, and administration interface.Project developed and maintained long-term, with continuous evolution, feature additions, and performance improvements.
- sebastien thuillierFreelance | React Native Developer – Confidential project for a major clientJune 2024 - June 2025 (1 year)Participated in a strategic project for a major client (under NDA), involving the design and development of a mobile application from scratch.Close collaboration with product and design teams to define features and user experience.Complete development of the mobile frontend in React Native, creating interfaces and integrating components for fluidity and ergonomics.Contributed to the design and architecture of the application, while respecting the security and performance constraints and requirements specific to a sensitive project.Participated in design meetings and followed iterations to ensure the final product perfectly met client needs.Fullstack and product-oriented approach, with a focus on user experience, performance, and code quality, while integrating best mobile development practices.
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Education
- RNCP Web and Mobile Web DeveloperIFA (French Institute of Business)2018développement web, js, php, bdd, html, css