Senior Software Engineer - Blockchain

As a Senior Software Engineer - Blockchain at Mastercard, you join the Blockchain and Digital Assets Engineering team to design, develop, and deliver high-performance Ethereum/EVM and Web3 solutions. You will work alongside talented engineers in a highly collaborative Agile environment, focusing on enterprise-grade architecture, scalability, security, and reliability. Your work will help architect and lead the future of commerce globally, bringing innovative payment solutions to market through blockchain technology.

What you'll do

• Design and develop scalable, production-grade smart contract systems and Web3 integrations within the Ethereum/EVM ecosystem.
• Lead technical design and architecture discussions, making sound engineering decisions while balancing scalability, security, performance, and maintainability.
• Translate complex business requirements into robust blockchain-based solutions aligned with enterprise standards and best practices.
• Participate in architecture reviews, code reviews, and technical design sessions to drive engineering excellence.
• Collaborate with product, compliance, security, and engineering teams throughout the software development lifecycle.
• Mentor and support engineers by sharing knowledge, promoting best practices, and fostering technical growth across the team.
• Evaluate emerging blockchain technologies, protocols, development frameworks, and industry trends to identify new opportunities and improvements.
• Contribute to the continuous evolution of engineering practices, tooling, automation, and software quality standards.
• Develop, test, deploy, and support applications and services in cloud-native, containerized environments.
• Champion secure coding practices and operational excellence across all phases of development and delivery.

What you bring

• Proven experience as a Software Engineer, Software Developer, or similar engineering role.
• Strong expertise in Ethereum/EVM and Web3 development using frameworks such as ethers.js, web3.js, or equivalent technologies.
• Proficiency in Solidity and hands-on experience designing, developing, and deploying production-grade smart contracts.
• Deep understanding of blockchain fundamentals, including consensus mechanisms, transaction lifecycle, gas optimization, wallet infrastructure, and security best practices.
• Experience with smart contract development frameworks such as Hardhat, Foundry, or similar toolchains.
• Strong knowledge of software engineering principles, system design, and modern development methodologies.
• Experience working with containerization and orchestration technologies such as Docker and Kubernetes.
• Familiarity with CI/CD pipelines and tools such as Jenkins or equivalent automation platforms.
• Proficiency with source control systems and collaborative development practices in multi-engineer environments.
• Experience building and maintaining automated unit, integration, and end-to-end testing solutions.
• Ability to make sound technical decisions, lead initiatives, and mentor engineers through influence rather than formal authority.
• Comfortable working autonomously in Agile environments while balancing competing priorities.
• Strong commitment to code quality, maintainability, security, and continuous improvement.
• Strong communication and collaboration skills, with the ability to explain technical concepts and influence decisions across technical and non-technical audiences.
• Bachelor's degree in Computer Science, Engineering, Information Systems, or equivalent practical experience.

Nice to have

• Experience with enterprise blockchain protocols such as Hyperledger Besu, Quorum, or Canton.
• Familiarity with Layer 2 scaling solutions, including Polygon, Arbitrum, or Optimism.
• Knowledge of smart contract security, common vulnerability patterns, and audit processes.
• Familiarity with non-EVM blockchain ecosystems, such as Solana.
• Proficiency in Java or another object-oriented backend programming language.
• Experience with Spring or Spring Boot.
• Familiarity with TypeScript and frontend frameworks such as React or Angular.
• Experience with AI and agentic engineering, including LLM integration, AI-powered developer tools, or autonomous agent frameworks.

What we offer

• Competitive base salary, with variation depending on location, job-related knowledge, skills, and experience.
• Annual bonus or commissions depending on the role.
• Insurance coverage including medical, prescription drug, dental, vision, disability, and life insurance.
• Flexible spending account and health savings account.
• 16 weeks of new parent leave and up to 20 days of bereavement leave.
• 80 hours of Paid Sick and Safe Time, 25 days of vacation time, and 5 personal days, pro-rated based on date of hire.
• 10 annual paid U.S. observed holidays.
• 401k with a best-in-class company match.
• Deferred compensation for eligible roles.
• Fitness reimbursement or on-site fitness facilities.
• Eligibility for tuition reimbursement.

About Mastercard

Mastercard powers economies and empowers people in over 200 countries and territories worldwide. The company supports a wide range of digital payments choices and works with customers to build a sustainable economy where everyone can prosper, making transactions secure, simple, smart, and accessible.