Web3 Frontend Engineer | React, DeFi & Blockchain UI

100% remotely or in our office: Warszawa

B2B: 110-130 PLN/H

Hi, Polcode here!

We’re a global, people-first software house matching ambitious developers with challenging projects. Our team of over 100 professionals helps build and improve digital businesses, software platforms, eCommerce stores, websites, apps, and everything in between. And they’re good at it.

We’re looking for an independent, proactive, and growth-oriented Frontend Developer (Web3/DeFi) to join our team and take part in an exciting project for one of our clients.You’ll build intuitive, secure, and high-performance interfaces for decentralized applications - enabling seamless interaction with smart contracts and on-chain data. This position is ideal for someone at least on a mid or senior level, passionate about Web3, blockchain integrations, and DeFi protocols, and eager to make a real impact in the decentralized space.It’s a long-term, full-time collaboration with plenty of room for learning, and contribution to cutting-edge blockchain products.

Get ready to:

• Craft responsive, accessible interfaces for Web3 and DeFi applications that feel effortless to use

• Build dynamic dashboards and visual tools that make interaction with on-chain data and smart contracts straightforward and engaging

• Collaborate with backend, product, and smart contract teams to turn complex blockchain ideas into clear, intuitive user experiences

• Take part in architecture discussions and help shape the technical direction through well-written documentation and thoughtful feedback

• Integrate Web3 functionality with tools like ethers.js, web3.js, or wagmi, connecting to wallets such as MetaMask, WalletConnect, and Ledger

• Ensure secure wallet operations and safe user transactions by following Web3 security best practices

• Keep our dApps fast and efficient, optimizing transaction flows, frontend performance, and gas usage

• Write modular, maintainable code with a strong focus on testing and long-term reliability

• Implement real-time data flows and live updates from blockchain networks and protocols

• Stay curious - explore and experiment with the latest Web3 frameworks, tools, and technologies to bring fresh perspectives to the product

What we are looking for:

• Solid frontend experience at a mid or higher level - ideally 3+ years working with React, TypeScript, and modern JavaScript (ES6+)

• Proven experience with Web3 integrations (ethers.js, web3.js, wagmi, thirdweb)

• Understanding of DeFi mechanics, smart contracts, and EVM-based blockchains

• Familiarity with wallet integrations (MetaMask, WalletConnect, Ledger, Trezor)

• Experience in state management (Redux, Zustand, Recoil or similar)

• Solid knowledge of CSS frameworks (Tailwind, styled-components, MUI)

• Experience with testing tools (Jest, React Testing Library, Cypress)

• Good understanding of CI/CD workflows, Git, and performance optimization

• Independent thinker with a problem-solving mindset, accuracy, and commitment to delivering high-quality results

• Comfortable working in a distributed team and communicating in English (min. B2)

It would be great if you also have:

• Experience working with multi-chain ecosystems and DeFi protocols

• Ability to read or write Solidity smart contracts and understand contract architecture

• Familiarity with The Graph, GraphQL, and on-chain indexing tools

• Experience with Next.js, Hardhat, or blockchain explorers (Etherscan APIs)

• Knowledge of Web3 security principles and dApp security layers

• Understanding of NFT standards (ERC-721, ERC-1155) and marketplaces

• Experience integrating hardware wallets and optimizing transaction signing UX

• Interest in contributing to open-source Web3 projects and exploring emerging blockchain frameworks

Tech stack you will work with:

• Frontend: React (main framework), with optional Vue.js or Svelte when needed

• Languages: TypeScript and modern JavaScript (ES6+)

• Web3 libraries: ethers.js, web3.js, wagmi, and thirdweb SDK

• Styling: Tailwind CSS, styled-components, and Material-UI for polished UIs

• Testing: Jest, React Testing Library, Cypress, and Playwright

• Build tools: Webpack and Vite to keep things fast and smooth

• APIs: REST, GraphQL, and JSON-RPC

• Wallets: MetaMask, WalletConnect, Coinbase Wallet, and Safe

Perks of being a #Polcoder:

• Multisport card, private medical care, life insurance, and meaningful gifts to celebrate important days

• Professional onboarding process

• We respect your private life - no overtime, no weekend jobs, work-life balance only, promise!

• Work at times that suit your daily rhythm, from the place of your choice

• Your work is appreciated - we believe in the power of feedback, also the one you give us

TL;DR

• 100% remote work

• 0% nonsense

We strongly believe that putting people first makes our work better.We encourage you to grow your career, contribute to open source, and follow your passion. We wanna do great things with you! 💜

Sounds like a match? Let’s talk!

If you’d like to know more or have any questions, reach out to Ela – she’s always open for a quick chat.