For Recruiters
Patryk Karasiński
Frontend Developer · React · React Native · TypeScript
Technical Skills
A detailed overview of the technologies and tools I work with on a daily basis.
Frontend
Mobile
Tools & Platforms
Backend
Work Experience
4+ years of commercial experience building web and mobile applications.
Front-End Developer
Treesat
Building web and mobile applications in the Automotive and Smart Home industries. Working in a production environment with multiple parallel projects.
- ✓Migrated bundler from Webpack to Vite — reduced developer cold-start time by ~70% and production build time by ~60%.
- ✓Migrated React Native from version 0.65 to 0.83 in an active production project — updated native dependencies, adjusted Gradle/Xcode configuration and resolved breaking changes.
- ✓Migrated multiple projects from JavaScript to TypeScript — introduced strict typing, eliminated runtime error classes and improved DX across the entire team.
- ✓Implemented Fastlane in mobile projects — automated the signing, building and distribution process for iOS and Android apps, eliminating manual release steps.
Full-Stack Developer
Freelancer
Building responsive web applications for various clients using React, Next.js and Astro. Full ownership of projects — from architecture to deployment.
My Projects
Check out some of my recent work. These projects showcase my skills and experience.
Health App
Web application for healthy eating.
SPA with client-server architecture. Frontend built in React with TypeScript and TanStack Query for server state management. REST API backend in Node.js/Express with MySQL. Deployed on Vercel (frontend) and Render (backend).
Veterinary Clinic
Web application for doctors and clients to use in the clinic.
Web application split into doctor and client panels. Frontend in React with Axios for API communication. Backend in Node.js/Express with MySQL. Project focused on clear UX for non-technical users.
Alert System
Web application to supervise life-saving alarms.
React application for real-time alarm monitoring. WebSocket-based architecture for live updates. TypeScript ensures type safety throughout the application.
Pins
Mobile application for tracking vehicle location.
Cross-platform mobile application in React Native with TypeScript. Integration with Google Maps API for real-time vehicle location tracking. Push notifications via Firebase Cloud Messaging (FCM).
Ferguson Home Panel
An application dedicated to tablets for managing Smart Home devices.
Dedicated tablet application in React Native for managing Ferguson Smart Home devices. UI optimized for large screens, handling IoT device communication protocols.
Availability
Currently open to new professional opportunities.
- Position
- Frontend Developer / React Developer
- Status
- Available for interviews
- Location
- Olsztyn, Poland / Remote
GitHub & Social
My code speaks for itself — feel free to browse my repositories.
Most of my repositories are private — I'm happy to discuss projects during a call.