Java Software Engineer Contract Jobs in Princeton, NJ

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Job Overview Citi is seeking a passionate and skilled Blockchain/Web3 Java Engineer to join the Citi Integrated Digital Assets Platform (CIDAP) engineering team. This is a hands-on engineering role for a developer who is deeply enthusiastic about the intersection of decentralized technologies and institutional finance. The successful candidate will contribute to the design, development, and deployment of Web3-native components and integrations that power Citi's digital asset infrastructure - spanning tokenization, smart contracts, on-chain settlement, and blockchain protocol integrations.

You will work within a collaborative, globally distributed team of engineers, architects, and business technologists who are building the next generation of institutional digital finance capabilities. We are looking for someone who brings strong Blockchain engineering fundamentals, a curiosity for emerging blockchain ecosystems, and the ability to bridge decentralized technology patterns with enterprise-grade software standards. Key Responsibilities Design, develop, and deploy Web3 components and integrations for Citi's Digital Asset Platform, including smart contracts, on-chain event listeners, wallet integrations, and blockchain protocol connectors Build and maintain backend services that interface with public and permissioned blockchain networks (e.g., Ethereum, Hyperledger Besu, Solana, Canton, or equivalent) Develop, test, and audit smart contracts written in Solidity or DAML or equivalent languages, ensuring security, correctness, and gas efficiency Integrate Web3 libraries and SDKs (e.g., Web3J, Web3JS, Ethers.js, Viem) into enterprise Java and/or Node.js backend services Implement asynchronous, event-driven architectures to handle on-chain events, transaction lifecycle management, and blockchain state synchronization Collaborate with architects and senior engineers to contribute to the design of scalable, secure, and resilient Web3 infrastructure Participate in code reviews, providing and receiving constructive technical feedback to maintain high engineering standards Support the integration of digital asset custody solutions, tokenization frameworks, and DeFi/TradFi bridging components Contribute to technical documentation, including smart contract specifications, integration guides, and architecture notes Stay current with the rapidly evolving Web3 ecosystem - tracking protocol upgrades, new token standards, Layer 2 solutions, and emerging tooling relevant to institutional use cases Work within Agile/Scrum frameworks, participating in sprint planning, stand-ups, and retrospectives within a distributed global team Help identify and resolve technical issues across the Web3 stack, escalating where appropriate to ensure delivery quality and timelines Qualifications / Experience Bachelor's degree in Computer Science, Engineering, or a related discipline; MS is a plus 12+ years of overall software engineering experience, with a strong backend development foundation 3 to 5 years of hands-on experience in Web3 and blockchain application development, including smart contract development and blockchain protocol integration 4 to 6 years of experience with backend development using Java/Spring, Node.js, or equivalent enterprise frameworks Proficiency in Solidity smart contract development, including testing frameworks (Hardhat, Foundry, Truffle) and security best practices Hands-on experience with Web3 libraries such as Web3J, Web3JS, Ethers.js, or Viem Solid understanding of blockchain fundamentals - consensus mechanisms, transaction lifecycle, gas models, wallet infrastructure, and key management Experience with token standards (ERC-20, ERC-721, ERC-1155, ERC-3525, or equivalent) and tokenization patterns Familiarity with blockchain networks (Hyperledger Besu, Solana or Canton) is a strong plus Experience with asynchronous programming, event-driven systems, and message queuing (Kafka, RabbitMQ, or equivalent) Familiarity with DevOps practices, containerization (Docker, Kubernetes), and CI/CD pipelines Understanding of cryptographic concepts - digital signatures, hashing, PKI, and secure key management - as applied to blockchain systems Exposure to Layer 2 scaling solutions (Polygon, Optimism, zkSync, etc.) and cross-chain interoperability protocols is a plus Experience in financial services or regulated industries is a plus Familiarity with Agile/Scrum methodologies and distributed team collaboration tools Competencies / Skills Web3 Engineering Depth: Strong command of the Web3 technology stack - from smart contract development to on-chain/off-chain integration patterns and blockchain node interaction Backend Engineering Fundamentals: Solid grounding in enterprise software engineering - API design, microservices, data structures, algorithms, and design patterns Security Mindset: Awareness of common smart contract vulnerabilities (reentrancy, front-running, integer overflow, etc.) and best practices for secure on-chain development Curiosity & Adaptability: Genuine enthusiasm for the Web3 ecosystem and the ability to rapidly learn and apply new protocols, standards, and tooling Collaborative Spirit: Strong team player who communicates clearly and constructively with engineers, architects, and non-technical stakeholders Delivery Orientation: Ability to manage personal delivery commitments, prioritize effectively, and produce high-quality output within sprint cycles Attention to Detail: Rigorous approach to testing, code quality, and documentation - particularly important given the immutable nature of on-chain deployments Tooling Proficiency: Working knowledge of engineering tools including Git, Jira, Jenkins, Hardhat/Foundry, Docker, Helm, and observability platforms Development Value As a Digital Assets Blockchain Java Engineer at Citi, you will be at the forefront of one of the most exciting and strategically significant technology domains in institutional finance

You will: Work on real-world, production-grade Web3 infrastructure at the scale and complexity of a global systemically important bank Gain deep exposure to institutional digital asset use cases - including tokenized securities, digital cash, on-chain settlement, and programmable finance Collaborate with world-class engineers, architects, and business leaders who are defining the future of digital finance at Citi Build expertise across both Web3-native and enterprise technology stacks, making you a uniquely versatile engineer in a rapidly growing field Access continuous learning opportunities, including emerging protocol research, industry conferences, and internal innovation programs Contribute to a platform with global reach and real commercial impact, with visibility across Citi's technology and business leadership ------------------------------------------------------ Job Family Group: Technology ------------------------------------------------------ Job Family: Applications Development ------------------------------------------------------ Time Type: Full time ------------------------------------------------------ Primary Location: New York New York United States ------------------------------------------------------ Primary Location Full Time Salary Range: $142,320.00 - $213,480.00 In addition to salary, Citi's offerings may also include, for eligible employees, discretionary and formulaic incentive and retention awards. Citi offers competitive employee benefits, including: medical, dental & vision coverage; 401(k); life, accident, and disability insurance; and wellness programs. Citi also offers paid time off packages, including planned time off (vacation), unplanned time off (sick leave), and paid holidays

For additional information regarding Citi employee benefits, please visit citibenefits.com. Available offerings may vary by jurisdiction, job level, and date of hire. ------------------------------------------------------ Most Relevant Skills Please see the requirements listed above

------------------------------------------------------ Other Relevant Skills For complementary skills, please see above and/or contact the recruiter. ------------------------------------------------------ Anticipated Posting Close Date: Aug 18, 2026 ------------------------------------------------------ Automated Processing and AI We use automated processing, including artificial intelligence, for our legitimate business interests (or our reasonable and appropriate business purposes) to identify and align the candidate's skills and abilities with a specific job opening. Additionally, if you so choose, or consent, we can match your skills and abilities to other suitable roles at Citi.

Importantly, all our hiring processes and decisions, including determining your suitability for a role, are conducted, checked, and decided by individuals. Our automated processing and AI do not involve relying on automatic or autonomous decision-making. Please refer to any Jurisdictional Considerations, with specific provisions for your country (where relevant) for further details.

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