SwapRail→

Wallet Engineer at SwapRail in Remote

ExperiencedRemotePart-timeRemote

Skills

javascripttypescriptweb3 librariesethers.jsviemweb3.jsevm transaction lifecyclewallet connection flowssigning flowsrpc providersnode inconsistenciescalldata constructiongas estimationfee optimizationnonce managementtransaction replacementre-org scenarioscollaborationproblem solvingmulti-chain environmentsethereumarbitrumbscpolygonaccount abstractionerc-4337smart contract interaction patternsmevslippagedefi protocols

Job Description

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