3 months 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 is a public financial-services company offering consumer and institutional banking, credit cards, wealth management, treasury and trade solutions, and capital-markets services. It serves individuals, corporations, financial institutions, and governments in more than 160 countries and jurisdictions, earning interest and fee income from lending, payments, trading, and advisory. Founded in 1812 and headquartered in New York, it trades on the NYSE under the ticker C.