Summary

As a founding Full Stack Engineer on the Polygon Fintech Labs team, you’ll work hand-in-hand with our Engineering Manager to build the foundation of our Financial Service application layer. Together, you’ll collaborate closely with product and design from day one to architect and ship high-impact features that bring real-world financial utility to millions of users.

You’ll build everything from backend services and wallet integrations to clean, intuitive user experiences that abstract away blockchain complexity — making stablecoin payments, programmable flows, and financial automation simple, secure, and accessible.

If you thrive on solving tough technical challenges and care deeply about creating polished user experiences, this is your opportunity to make a lasting impact at the intersection of crypto and fintech.

Your Responsibilities

1. Implement wallet and transaction features that enable stablecoin payments, cross-chain bridging, and programmable flows.
2. Integrate third-party wallet SDKs and APIs from key partners like Crossmint to support onboarding, compliance flows, and seamless fiat on/off ramps.
3. Develop robust backend infrastructure and services to enable secure transaction execution, smart contract interactions, and vault access.
4. Collaborate closely with smart contract engineers to connect on-chain logic with performant backend and frontend systems.
5. Work side-by-side with frontend engineers to deliver secure, fast, and delightful user experiences.
6. Contribute to architectural decisions that prioritize scalability, security, code quality, and system reliability across the stack.

What You’ll Need

1. 4+ years of full stack engineering experience, ideally in crypto, fintech, or API-intensive environments.
2. Strong proficiency with modern TypeScript and frameworks such as Node.js, NestJS, or similar.
3. Hands-on experience integrating third-party SDKs (wallets, bridges, KYC tools) into production-grade systems.
4. Solid understanding of Ethereum and EVM-compatible smart contracts and how to interact with them via backend/frontend code.
5. Familiarity with secure key management systems, vault integrations, or encrypted storage solutions.
6. Proven ability to ship clean, maintainable, production-ready code in a fast-paced, collaborative setting.

Preferred Qualifications

1. Experience working with smart contract wallets or account abstraction flows.
2. Background building scalable backend services for mobile-first applications.
3. Knowledge of cross-chain bridging technologies and relayer infrastructure.

Skills

• Development
• Smart Contract Development
• Software Engineering
• Team Collaboration
• TypeScript