Senior Web3 Blockchain Engineer – Digital Assets

Citigroup Inc.; New York (NY); On-site; USD 142,000 - 213,000; Full time

Job summary

Citi is seeking a Digital Assets Web3 Blockchain Engineer to join the CIDAP team in New York. This hands-on role focuses on building Web3-native components, smart contracts, and integrations that power Citi's institutional digital asset platform.

You will work with a global team of engineers to design secure, scalable, and enterprise-grade Web3 infrastructure, emphasizing tokenization, on-chain settlement, and cross-network interoperability. Experience in Java/Spring and Web3 libraries is valued.

Qualifications

• Bachelor's degree in Computer Science, Engineering, or a related discipline; MS is a plus
• 10 to 15 years of overall software engineering experience, with a strong backend development foundation
• 3 to 5 years of hands-on experience in Web3 and blockchain application development, including smart contract development and blockchain protocol integration
• 8 to 12 years of experience with backend development using Java/Spring, Node.js, or equivalent enterprise frameworks
• Proficiency in smart contract development, including testing frameworks (Hardhat, Foundry, Truffle) and security best practices
• Hands-on experience with Web3 libraries such as Web3J, Web3JS, Ethers.js, or Viem
• Solid understanding of blockchain fundamentals - consensus mechanisms, transaction lifecycle, gas models, wallet infrastructure, and key management
• Experience with token standards (ERC-20, ERC-721, ERC-1155, ERC-3525, or equivalent) and tokenization patterns
• Familiarity with blockchain networks (Hyperledger Besu, Solana, Canton) is a strong plus
• Experience with asynchronous programming, event-driven systems, and message queuing (Kafka, RabbitMQ, or equivalent)
• Familiarity with DevOps practices, containerization (Docker, Kubernetes), and CI/CD pipelines
• Understanding of cryptographic concepts - digital signatures, hashing, PKI, and secure key management - as applied to blockchain systems
• Exposure to Layer 2 scaling solutions (Polygon, Optimism, zkSync, etc.) and cross-chain interoperability protocols is a plus
• Experience in financial services or regulated industries is a plus
• Familiarity with Agile/Scrum methodologies and distributed team collaboration tools

Responsibilities

• Design, develop, and deploy Web3 components for Citi's Digital Asset Platform, including smart contracts and wallet integrations
• Build and maintain backend services that interface with public and permissioned blockchain networks
• Develop, test, and audit smart contracts written in Solidity or equivalent
• Integrate Web3 libraries (Web3J, Web3JS, Ethers.js, Viem) into enterprise Java and/or Node.js backend services
• Implement asynchronous, event-driven architectures to handle on-chain events and state synchronization
• Collaborate with architects and senior engineers to design scalable Web3 infrastructure
• Participate in code reviews and provide constructive feedback
• Support integration of digital asset custody, tokenization frameworks, DeFi/TradFi bridging components
• Contribute to technical documentation
• Stay current with Web3 ecosystem and protocol upgrades
• Work within Agile/Scrum frameworks in a distributed global team
• Help identify and resolve technical issues across the Web3 stack

Skills

Web3 development

Java/Spring

Node.js

Smart contracts

Security testing

DevOps

Education

Bachelor's degree in CS/Engineering

MS degree preferred

Tools

Web3J

Web3JS

Ethers.js

Viem

Hardhat/Foundry

Docker

Kubernetes

Job description

Citi is seeking a Digital Assets Web3 Blockchain Engineer to join the CIDAP team in New York. This hands-on role focuses on building Web3-native components, smart contracts, and integrations that power Citi's institutional digital asset platform.

You will work with a global team of engineers to design secure, scalable, and enterprise-grade Web3 infrastructure, emphasizing tokenization, on-chain settlement, and cross-network interoperability. Experience in Java/Spring and Web3 libraries is valued.