1 month ago
London, United KingdomSenior
Responsibilities
- Design, develop, and deploy Web3 components including smart contracts, on-chain event listeners, wallet integrations, and blockchain protocol connectors.
- Build and maintain backend services interfacing with public and permissioned blockchain networks.
- Develop, test, and audit Solidity smart contracts for security, correctness, and gas efficiency.
- Integrate Web3 libraries and SDKs into enterprise Java and Node.js backend services.
- Implement asynchronous, event-driven architectures for on-chain events, transaction lifecycles, and blockchain state synchronization.
- Support digital asset custody, tokenization, DeFi, and TradFi bridging integrations.
- Collaborate on scalable, secure, and resilient Web3 infrastructure through design reviews, code reviews, documentation, and issue resolution.
- Track Web3 protocol upgrades, token standards, Layer 2 solutions, and emerging institutional tooling while working within Agile/Scrum sprint cycles.
Requirements
- Bachelor’s degree in Computer Science, Engineering, or a related discipline; a master’s degree is a plus.
- Extensive software engineering experience with a strong backend development foundation and hands-on Web3 or blockchain application development experience.
- Experience with Java/Spring, Node.js, or equivalent enterprise frameworks.
- Proficiency in Solidity, including Hardhat, Foundry, or Truffle testing frameworks and smart contract security practices.
- Experience with Web3J, Web3JS, Ethers.js, or Viem.
- Understanding of blockchain consensus, transaction lifecycles, gas models, wallet infrastructure, key management, and token standards including ERC-20, ERC-721, ERC-1155, or ERC-3525.
- Experience with asynchronous programming, event-driven systems, and Kafka, RabbitMQ, or equivalent messaging technologies.
- Familiarity with Hyperledger Besu, Solana, Canton, Docker, Kubernetes, CI/CD pipelines, cryptographic concepts, Layer 2 solutions, and cross-chain interoperability protocols.
- Financial services or regulated-industry experience, Agile/Scrum familiarity, distributed-team collaboration, and knowledge of Git, Jira, Jenkins, Helm, and observability platforms are valued.
Benefits
- London hybrid working model with up to 2 days working from home per week.
- 27 days of annual leave plus bank holidays.
- Discretionary annual performance-related bonus.
- Private medical care and life insurance.
- Employee assistance program, pension plan, and paid parental leave.
- Employee discounts and access to learning and development resources, industry conferences, and internal innovation programs.
Tech Stack
Categories
About Citi
Citi's mission is to serve as a trusted partner to our clients by responsibly providing financial services that enable growth and economic progress. Our core activities are safeguarding assets, lending money, making payments and accessing the capital markets on behalf of our clients. We have over 200 years of experience helping our clients meet the world's toughest challenges and embrace its greatest opportunities. We are Citi, the global bank – an institution connecting millions of people across hundreds of countries and cities. For information on Citi’s commitment to privacy, visit on.citi/privacy.