Open to opportunities

Mateusz Niznik

@mateuszniznik

Message

I build and ship React Native, web, and AI-powered products from architecture to deployment.

United States

Message

What I'm looking for

I'm looking to build web, mobile, and AI-powered products end to end, combining hands-on engineering, architecture, product delivery, and collaborative startup or production-team work.

I've built and shipped AI-powered tools, startup MVPs, and mobile applications through Niznik Interactive, MintCollect, and SentiKits. At MintCollect, I built a React Native trading-card data application from scratch, while at SentiKits I architected a React Native app and Node.js backend with subscriptions, authentication, REST APIs, and Shopify integration.

I've owned products end to end across frontend architecture, backend APIs, deployment, and technical direction. As a technical product manager at Zippia, I improved product iteration efficiency by 42% through a structured unit-testing framework and reduced résumé-builder user drop-off by 17% after resolving a UX issue.

I also teach mobile and web development at Bethesda University of California, creating real-world programming projects and integrating AI tools into education. My work spans React, React Native, Node.js, Python, AWS, API design, system architecture, product delivery, and cross-functional leadership.

Experience

Work history, roles, and key accomplishments

Current

Founding Software Engineer

Current

MintCollect

Apr 2026 - Present (4 months)

Built a React Native mobile application from scratch for a trading card data platform. Designed and implemented the frontend software architecture using TypeScript and Expo, integrated REST APIs for real-time data retrieval, and collaborated directly with founders in a fast-paced startup environment.

React Native TypeScript Expo REST APIs Software Architecture