Blockchain Web3 Engineer (100% Onsite - FTE)

Job ID: 410999 Job Title: Blockchain Web3 Engineer Location: New York City, NY Onsite Must Have Technical/Functional Skills • Core Web3 / Blockchain Skills (Must-Have) • Strong understanding of blockchain fundamentals: • transactions, blocks, gas/fees, wallets/keys, RPC, finality, consensus basics • Hands-on experience with smart contracts: • Solidity (preferred) and development tooling (Hardhat/Foundry/Truffle/Remix) • Experience working with EVM-based chains (Ethereum/Polygon/Arbitrum/Optimism/BSC) • or enterprise chains (Hyperledger Fabric/Corda/Quorum) depending on project Roles & Responsibilities • Smart Contract Engineering & Web3 Development • Design, develop, and maintain smart contracts (Solidity/Vyper or relevant stack) aligned to product and security requirements. • Build backend/Web3 components for contract interaction: • Transaction orchestration, signature flows, nonce management, gas strategies • Web3 SDK integrations • Develop and manage contract deployment pipelines, including ABI/versioning, migrations, upgrade strategies (proxy patterns), and release coordination. • Implement secure patterns for contracts: • Support smart contract testing: • Node Operations & Infrastructure • Deploy, configure, and operate blockchain nodes and supporting infrastructure: • Full nodes/archival nodes, RPC endpoints, validator nodes (as applicable) • Manage node upgrades, chain configuration changes, and incident response for production networks. • Implement operational tooling for: • Node health checks, RPC performance monitoring, log aggregation, and alerting • Handle blockchain-specific reliability concerns: • Re-org handling, finality considerations, peer connectivity, RPC failover, rate limiting “Cleo Consulting is an equal opportunity employer (Minorities/Women/Veterans/Disabled)”