Senior Web3 Backend Engineer, Blockchain Platform

Citi; Greater London; Hybrid; GBP 90,000 - 120,000; Full time

Benefits offered by this job

27 days annual leave

Annual performance bonus

Private Medical Care & Life Insurance

Pension Plan

Employee Assistance Program

Learning & development resources

Hybrid working model

Job summary

Citi London is seeking a Lead Web3 Engineer to drive backend development for the Integrated Digital Assets Platform. You will build enterprise-grade web applications, connect to blockchain networks, and develop APIs and services that enable tokenized assets and digital infrastructure.

The role requires strong Java/Spring experience, familiarity with Web3 tools, and a proactive, collaborative mindset. A hybrid work model with strong engineering standards and ongoing learning opportunities is

Qualifications

• Bachelor’s degree in CS or Engineering; MS/PhD in computer science, or related discipline a plus.
• Extensive experience in full software development and testing lifecycle.
• Proven experience with Backend web development using Java Spring
• Solid experience in web3 application development
• Familiarity with asynchronous programming and scalable web apps
• Knowledge of Web3 libraries like Web3J and Web3JS

Responsibilities

• Develop, test, and maintain backend components and services that integrate with blockchain networks and digital asset infrastructure
• Implement blockchain integrations including node connectivity, transaction submission, on-chain event monitoring, and wallet interactions using enterprise Java and Web3 libraries
• Write, test, and deploy smart contracts in Solidity or equivalent languages following security and quality standards
• Build and maintain APIs and microservices exposing blockchain functionality to platform consumers
• Implement asynchronous and event-driven processing for transaction lifecycle and data synchronization
• Participate in code reviews and ensure high standards of quality and test coverage
• Collaborate with architects, engineers and product teams to translate requirements into maintainable software
• Contribute to technical documentation including design notes, APIs and integration guides
• Support debugging and resolution across the blockchain stack in development and production
• Follow engineering best practices, coding standards and Agile delivery processes
• Stay informed of blockchain/Web3 developments and emerging standards
• Participate in sprint ceremonies as part of an Agile/Scrum team

Skills

Java Spring

Web3 Development

Blockchain Knowledge

Security Best Practices

Code Review

Team Collaboration

Testing & QA

DevOps Basics

Education

Bachelor's degree in CS/Engineering

MS/PhD in CS (plus)

Tools

Git

Jira

Jenkins

Docker

Hardhat/Foundry

Web3J/Web3JS

Job description

Citi London is seeking a Lead Web3 Engineer to drive backend development for the Integrated Digital Assets Platform. You will build enterprise-grade web applications, connect to blockchain networks, and develop APIs and services that enable tokenized assets and digital infrastructure.

The role requires strong Java/Spring experience, familiarity with Web3 tools, and a proactive, collaborative mindset. A hybrid work model with strong engineering standards and ongoing learning opportunities is