Build secure, reliable, and scalable wallet integrations and transaction flows for the SwapRail platform, focusing on connectivity, signing, and execution across multiple chains.
Location: Remote / Work from Home
Type: Part-time preferred / Full-time available
Responsibilities
- Integrate major Web3 wallets (e.g., MetaMask, WalletConnect, Coinbase Wallet) across web and mobile environments
- Design and implement secure transaction signing pipelines (EIP-1559, EIP-712, typed data, permit flows)
- Build robust wallet connection systems, including session persistence, reconnection, and multi-account handling
- Implement transaction building logic, including calldata construction, batching, and multi-step execution flows
- Develop gas estimation, fee optimization, and fallback strategies across different networks
- Handle edge cases such as nonce management, transaction replacement (speed up / cancel), and re-org scenarios
- Collaborate with backend teams on routing, simulation, and execution layers
- Work closely with frontend teams to ensure seamless UX for wallet interactions and transaction confirmations
- Ensure high security standards in key handling, signing flows, and user interaction surfaces
Requirements
- Strong proficiency in JavaScript / TypeScript
- Hands-on experience with Web3 libraries (ethers.js, viem, web3.js)
- Deep understanding of EVM transaction lifecycle and structure
- Experience implementing wallet connection and signing flows in production
- Familiarity with RPC providers, node inconsistencies, and network reliability issues
- Experience building or contributing to Web3 applications (DEX, wallet, aggregator, etc.)
Nice to Have
- Experience with multi-chain environments (Ethereum, Arbitrum, BSC, Polygon, etc.)
- Familiarity with account abstraction (ERC-4337)
- Experience with smart contract interaction patterns (multicall, proxy, upgradeable contracts)
- Understanding of MEV, slippage, and transaction execution risks
- Experience working on DeFi protocols or trading-related products
Skills Required
- Strong proficiency in JavaScript / TypeScript
- Hands-on experience with Web3 libraries (ethers.js, viem, web3.js)
- Deep understanding of EVM transaction lifecycle and structure
- Experience implementing wallet connection and signing flows in production
- Familiarity with RPC providers, node inconsistencies, and network reliability issues
- Experience building or contributing to Web3 applications (DEX, wallet, aggregator, etc.)
What We Do
SwapRail builds next-generation infrastructure for decentralized liquidity routing and cross-protocol execution. The company focuses on creating secure and reliable blockchain transaction infrastructure and a trusted self-custody wallet for seamless cross-chain swaps. Their mission is to provide a professional wallet experience for cross-chain movement, allowing users to hold assets safely and move value across chains with clear routing and pre-sign fee visibility.
