Wallet Engineer at SwapRail

<p style="min-height:1.5em">Build secure, reliable, and scalable wallet integrations and transaction flows for the SwapRail platform, focusing on connectivity, signing, and execution across multiple chains.</p><p style="min-height:1.5em"></p><p style="min-height:1.5em"><strong>Location:</strong> Remote / Work from Home</p><p style="min-height:1.5em"><strong>Type:</strong> Part-time preferred / Full-time available</p><p style="min-height:1.5em"></p><p style="min-height:1.5em">Responsibilities</p><p style="min-height:1.5em">- Integrate major Web3 wallets (e.g., MetaMask, WalletConnect, Coinbase Wallet) across web and mobile environments</p><p style="min-height:1.5em">- Design and implement secure transaction signing pipelines (EIP-1559, EIP-712, typed data, permit flows)</p><p style="min-height:1.5em">- Build robust wallet connection systems, including session persistence, reconnection, and multi-account handling</p><p style="min-height:1.5em">- Implement transaction building logic, including calldata construction, batching, and multi-step execution flows</p><p style="min-height:1.5em">- Develop gas estimation, fee optimization, and fallback strategies across different networks</p><p style="min-height:1.5em">- Handle edge cases such as nonce management, transaction replacement (speed up / cancel), and re-org scenarios</p><p style="min-height:1.5em">- Collaborate with backend teams on routing, simulation, and execution layers</p><p style="min-height:1.5em">- Work closely with frontend teams to ensure seamless UX for wallet interactions and transaction confirmations</p><p style="min-height:1.5em">- Ensure high security standards in key handling, signing flows, and user interaction surfaces</p><p style="min-height:1.5em"></p><p style="min-height:1.5em">Requirements</p><p style="min-height:1.5em">- Strong proficiency in JavaScript / TypeScript</p><p style="min-height:1.5em">- Hands-on experience with Web3 libraries (ethers.js, viem, web3.js)</p><p style="min-height:1.5em">- Deep understanding of EVM transaction lifecycle and structure</p><p style="min-height:1.5em">- Experience implementing wallet connection and signing flows in production</p><p style="min-height:1.5em">- Familiarity with RPC providers, node inconsistencies, and network reliability issues</p><p style="min-height:1.5em">- Experience building or contributing to Web3 applications (DEX, wallet, aggregator, etc.)</p><p style="min-height:1.5em"></p><p style="min-height:1.5em">Nice to Have</p><p style="min-height:1.5em">- Experience with multi-chain environments (Ethereum, Arbitrum, BSC, Polygon, etc.)</p><p style="min-height:1.5em">- Familiarity with account abstraction (ERC-4337)</p><p style="min-height:1.5em">- Experience with smart contract interaction patterns (multicall, proxy, upgradeable contracts)</p><p style="min-height:1.5em">- Understanding of MEV, slippage, and transaction execution risks</p><p style="min-height:1.5em">- Experience working on DeFi protocols or trading-related pro