Senior Fullstack Developer – SDK Team (React + Node.js) 📍 Remote | Full-time | B2B

Remote | Full-time | B2B

About Pay.com

Pay.com builds payment solutions for e-commerce businesses worldwide. One of our most critical products is our JavaScript SDK -- a library integrated directly into merchants' websites to power checkout flows at global scale. We're looking for someone who takes full ownership of this product: not just writes code, but understands the technical consequences of every decision for thousands of end users.

Responsibilities

• Design, develop, and maintain our SDK and developer-facing tools

• Ensure a seamless integration experience for Pay.com merchants

• Write well-tested, documented, and maintainable code

• Collaborate closely with Product, Engineering, and Support

• Own features end-to-end -- from technical design through release

Requirements

• 5+ years of professional software engineering experience

• Strong expertise in JavaScript (ES6+) and TypeScript

• Proven experience with React.js and Node.js

• Deep understanding of frontend performance, accessibility, and cross-browser compatibility

• Ability to work autonomously and take full ownership of product areas

• Strong communication skills and product mindset

Nice to have

• Experience working on SDKs, libraries, or embeddable components

What we offer

• 19,000 – 25,000 PLN net / month (B2B)

• Remote-first -- work from anywhere

• Real impact -- our SDK powers payments on merchants' websites at global scale

• Autonomy and trust in technical decision-making

• A high-standards engineering team that cares about code quality