Wallet Engineer

Build secure, reliable, and scalable wallet integrations and transaction flows for the Biti platform, focusing on connectivity, signing, and execution across multiple chains.

Key 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

Qualifications & 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.)

Preferred / Nice-to-Have Qualifications

• 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