Senior Blockchain Developer

As a Senior Blockchain Developer at Luxoft, you join a Modernization as a Service practice supporting our client, a leading financial institution in the UK. You design, build, and deploy Web3 components including smart contracts, event listeners, wallet integrations, and protocol connectors for a digital asset platform.

What you'll do

• Design, build, and deploy Web3 components including smart contracts, event listeners, wallet integrations, and protocol connectors for a digital asset platform
• Develop backend services using Java/Spring and Node.js to interface with public and permissioned blockchains through SDKs such as Web3J, Ethers.js, and Viem
• Write, test, and audit Solidity contracts to ensure security, correctness, and gas efficiency
• Implement event-driven architectures to handle on-chain events, transaction lifecycles, and state synchronization
• Support tokenization, custody, and DeFi/TradFi bridging integrations, contributing to architectural and design decisions
• Maintain engineering standards by performing code reviews, producing documentation, and participating in Agile delivery within a distributed global team

What you bring

• Solidity development with hands-on testing using Hardhat, Foundry, or Truffle, following security best practices and optimizing for gas efficiency
• Proficiency with Web3 libraries such as Web3J, Web3JS, Ethers.js, and Viem integrated into enterprise backends
• Strong backend engineering skills in Java/Spring and/or Node.js with experience in API design, microservices, and design patterns
• Deep blockchain fundamentals knowledge including consensus mechanisms, transaction lifecycle, gas models, wallet infrastructure, and key management
• Understanding of token standards including ERC-20, ERC-721, ERC-1155, ERC-3525 and tokenization patterns
• Experience designing and implementing event-driven and asynchronous architectures, including on-chain event listeners, state synchronization, and message queuing systems such as Kafka or RabbitMQ
• Applied cryptography knowledge covering digital signatures, hashing, PKI, and secure key management
• DevOps proficiency with Docker, Kubernetes, Helm, CI/CD tools such as Jenkins, Git, Jira, and observability tooling
• BSc in Computer Science or Engineering with extensive overall software engineering experience and proven hands-on Web3 delivery
• Security mindset with awareness of reentrancy, front-running, and integer overflow vulnerabilities
• Attention to detail and rigour driven by the immutability of on-chain deployments
• Ability to communicate clearly with engineers, architects, and non-technical stakeholders
• Self-managed delivery within Agile/Scrum sprints and distributed global team collaboration

Nice to have

• Experience with permissioned and alternative networks such as Hyperledger Besu, Canton, or Solana
• Knowledge of Layer 2 solutions including Polygon, Optimism, zkSync and cross-chain interoperability
• MSc qualification

What we offer

• Remote position based in the United Kingdom