Freelance Fullstack Developer
Rare fullstack versatility — from product to code, without compromise.
React, Next.js and TypeScript at the core, mobile apps, backend APIs and blockchain fundamentals on top — 4 years and 9 months of hands-on experience, including missions shipped to real production. Available immediately.
Positioning
I design and ship web and mobile products end to end — from technical architecture to the final interface — for startups that need to move fast, SMEs that need a reliable long-term partner, and agencies looking for an autonomous developer who can plug in without friction.
My strength isn't mastering a single framework to perfection, but covering the entire chain: React and Next.js interfaces, React Native mobile apps, Node.js and NestJS APIs, all the way to blockchain development fundamentals — a rare skill among generalist fullstack developers, acquired through dedicated training and applied on real projects (staking dApp, on-chain interactions).
This versatility isn't a marketing claim: it's what lets me take full ownership of a project, set up a sound architecture from day one, and avoid the costly back-and-forth between several specialized providers.
Featured projects
06 selectedWeb · E-commerce & back-office
Lalaina Création - Cashmere Boutique
Showcase site and online boutique for a handmade cashmere knitwear atelier (100% cashmere), with a full back-office: stock management with low-stock alerts, custom-order tracking, alteration quotes, promotions, and per-product QR label generation.
Boutique + full business back-office shipped for a real client.
Web · Showcase & leads
MB Conseils - Commercial Real Estate
Showcase site for a commercial real estate agency (offices, retail, warehouses): filterable property catalogue, online estimation request with photo upload, and a back-office for managing listings and incoming leads.
SaaS · Complete product
Wedding-Hat
All-in-one wedding planning SaaS backed by an AI recommendation assistant — budget, vendors, guests, and planning brought together in one tool.
The most complete product in the portfolio, from functional design to deployment.
Business platform · Production
G-Formation
Training platform built and deployed to production for a real company, with Microsoft Teams / Graph API integration.
Used daily by the client company's internal teams.
Web · Real-time
Stocks-App
Real-time stock market platform with advanced TradingView charts and AI-assisted market analysis.
Web · Product & UX
Sportizer
Basketball scoreboard with a dual interface: a remote control for the operator, a synced screen for the audience.
Designed as a real two-interface product, not a simple counter.
Web3 · Differentiator
Staking DApp
Decentralized staking application: wallet connection, deposits, yield calculation, and on-chain interactions.
Concrete proof of the blockchain skill that sets this profile apart.
SaaS · AI & payments
SmoldAI - AI SaaS
Multi-AI SaaS with authentication, Stripe payments, and full subscription management.
End-to-end SaaS proof of skill: auth, payments, AI.
Tech stack
Core skills
ReactNext.jsTypeScriptTailwindCSSAdvanced
React NativeVue.jsLaravelDockerIntermediate
C#
PythonJunior
Professional experience
Internship
Full-Stack Developer - Gestimum
Self-training on Vue.js and Laravel. Development of a training website (G-Formation). First contributions to business-oriented applications in a professional environment.
Apprenticeship — 3 years
Full-Stack Developer - Gestimum
Development and maintenance of business-oriented web and mobile applications (Next.js, TypeScript, Tailwind CSS, React Native). Enhancement of the G-Formation platform with advanced customization for training sales. Design and development of a React Native mobile app connected to the Gestimum CRM. Full redesign of the Gestimum private area. Development of an internal ticket management application. Creation of Express.js APIs for integrations between Gestimum and external clients.
Permanent contract — 1 year 9 months
Web & Mobile / Full-Stack Developer - Gestimum
Participation in technical architecture and continuous performance improvement. Creation of an AI assistant specialized in Gestimum documentation and WebServices (Ollama, OpenWebUI). Development of secure middleware for Gestimum WebServices (authentication, routing, and secured data flows). Deployment and supervision of production applications (Docker / GitLab CI/CD). Migration of all applications to an Ubuntu server and full Docker containerization. Implementation of automatic transactional emails and notifications.
Certification — 3 months
dApp Developer - Alyra Certification
Design and deployment of Solidity smart contracts on EVM networks (testnet / mainnet). Development of a React/Next.js dApp interface connected through Wagmi. Unit and integration testing with Hardhat and Ganache. Wallet, signature, and on-chain transaction management with MetaMask and WalletConnect. Exploration of ERC-20, ERC-721 (NFT), and ERC-1155 standards. Smart contract hardening with OpenZeppelin (reentrancy and access control).
Today
Freelance fullstack developer
Launching independent practice — available immediately for new missions.
Available immediately
Have a project in mind? Let's talk, no strings attached.
Indicative day rate: €250 – €400 / day, depending on project scope.
thomas.jankowski.dev@gmail.com