Senior Blockchain Developer

Project description

Modernization as a Service (MaaS) is a cross-functional practice supporting all business verticals within the company.

We are seeking a Senior Blockchain Developer to join our project with our client, a leading financial institution in the UK.

Responsibilities

• - 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.
  
  

  SKILLS

  Must have

  • Core / must-have:
  • Smart contracts: Solidity development, testing (Hardhat, Foundry, Truffle), security best practices, gas efficiency
  • Web3 libraries: Web3J, Web3JS, Ethers.js, Viem — integrated into enterprise backends
  • Backend engineering: Java/Spring and/or Node.js, API design, microservices, design patterns
  • Blockchain fundamentals: consensus mechanisms, transaction lifecycle, gas models, wallet infrastructure, key management
  • Token standards: ERC-20, ERC-721, ERC-1155, ERC-3525 and tokenization patterns
  • Event-driven / async architecture: on-chain event listeners, state synchronization, message queuing (Kafka, RabbitMQ)
  • Cryptography applied to blockchain: digital signatures, hashing, PKI, secure key management
  • DevOps: Docker, Kubernetes, Helm, CI/CD (Jenkins), Git, Jira, observability tooling
  • Education: BSc in CS/Engineering; extensive overall software engineering experience with proven hands-on Web3 delivery

  Soft skills / competencies

  • Security mindset (reentrancy, front-running, integer overflow awareness)
  • Attention to detail and rigour - driven by the immutability of on-chain deployments
  • Curiosity and fast adaptation to a rapidly evolving ecosystem
  • Clear communication with engineers, architects, and non-technical stakeholders
  • Self-managed delivery within Agile/Scrum sprints, distributed global team collaboration
  • Code review participation and technical documentation
  
  

  Nice to have

  - Permissioned/alternative networks: Hyperledger Besu, Canton, Solana Layer 2 (Polygon, Optimism, zkSync) and cross-chain interoperability

• Digital asset custody, DeFi/TradFi bridging
• Financial services or other regulated-industry background
• MSc