We are seeking a talented and experienced Senior Software Engineer to join our Instant Payments Technology team, contributing to the development and evolution of our next-generation Instant Payments Platform. In this role, you will combine your deep technical expertise with a solid understanding of payments processing to design, develop, and maintain robust, scalable, and secure solutions. You will be involved in all aspects of the software development lifecycle, leveraging technologies like Java, Spring Boot, Kafka, MongoDB, and AWS to deliver innovative and reliable payment solutions. Your contributions will directly impact the performance and functionality of a critical platform powering real-time financial transactions.Responsibilities:<ul><li>Payments Solutions Development: Design, develop, and implement Java-based microservices and applications within a cloud-native AWS environment, specifically tailored for instant payments processing.</li><li>Core Payments Functionality: Work on core payments functionalities including transaction processing, fraud detection, regulatory compliance (KYC/AML), settlement, and reconciliation.</li><li>Cloud Infrastructure &amp; Deployment: Deploy, manage, and monitor applications within AWS, optimizing performance and scalability for high-volume payment transactions. Automate infrastructure deployment and configuration using Infrastructure as Code (IaC) principles.</li><li>Event-Driven Architecture: Build and integrate with event-driven systems using Kafka to ensure real-time data processing and asynchronous communication for payments events.</li><li>Database Design &amp; Optimization: Design and optimize MongoDB schemas to efficiently manage payments data, ensuring data integrity and performance for high-throughput transactions.</li><li>API Development &amp; Integration: Develop and maintain RESTful APIs for internal and external integration with the Instant Payments Platform. Ensure API security and compliance with industry standards.</li><li>Quality Assurance &amp; Testing: Implement robust unit, integration, and performance testing strategies to ensure the reliability and accuracy of payment processing logic. Participate in code reviews and contribute to maintaining high code quality standards.</li><li>Security &amp; Compliance: Implement and adhere to security best practices for payment systems, ensuring compliance with relevant regulations (e.g., PCI DSS).</li><li>Collaboration &amp; Communication: Collaborate effectively with product managers, business analysts, and other engineers to define requirements and deliver high-quality payment solutions. Communicate effectively on technical topics related to payment processing.</li><li>Incident Management &amp; Support: Participate in on-call rotation to provide support for the Instant Payments Platform, troubleshooting and resolving production issues related to payment processing.</li></ul>Qualifications:<ul><li>6+ years of experience in software development with a strong focus on Java-based enterprise applications.</li><li>Preferred experience in the payments industry, with a solid understanding of payment processing concepts, protocols, and technologies (e.g., ISO 8583, SEPA, SWIFT).</li><li>Proficiency in Java, Spring Boot, Kafka, and MongoDB.</li><li>Preferred Hands-on experience with AWS cloud services and cloud-native architectures.</li><li>Experience developing and deploying microservices.</li><li>Strong understanding of RESTful API design and development.</li><li>Solid understanding of database design principles and experience with NoSQL databases (MongoDB preferred).</li><li>Experience with event-driven architectures and message queueing systems (Kafka preferred).</li><li>Familiarity with CI/CD pipelines and tools.</li><li>Strong understanding of software security principles and best practices, particularly in the context of payment systems.</li><li>Excellent problem-solving, communication, and collaboration skills.</li><li>Experience with Agile development methodologies.</li></ul>Education:<ul><li>Bachelors degree in Computer Science, Engineering, or a related field.</li><li>Masters degree preferred.</li><li>Relevant certifications in payments technology or cloud computing are a plus.</li></ul>This job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.------------------------------------------------------Job Family Group: Technology------------------------------------------------------Job Family:Applications Development------------------------------------------------------Time Type:Full time------------------------------------------------------Primary Location:Tampa Florida United States------------------------------------------------------Primary Location Full Time Salary Range:$113,840.00 - $170,760.00 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 &amp; 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 AWS Cloud9, Cloud Computing, Digital Payments, Java.------------------------------------------------------Anticipated Posting Close Date:Oct 13, 2025------------------------------------------------------Citi is an equal opportunity employer, and qualified candidates will receive consideration without regard to their race, color, religion, sex, sexual orientation, gender identity, national origin, disability, status as a protected veteran, or any other characteristic protected by law. If you are a person with a disability and need a reasonable accommodation to use our search tools and/or apply for a career opportunity review <a href="https://www.citigroup.com/citi/accessibility/application-accessibility.htm" target="_blank">Accessibility at Citi</a>. View Citi’s <a href="https://www.citigroup.com/global/eeo-aa-policy" target="_blank">EEO Policy Statement</a> and the <a href="https://www.eeoc.gov/sites/default/files/2023-06/22-088_EEOC_KnowYourRights6.12ScreenRdr.pdf" target="_blank">Know Your Rights</a> poster.