Job ID: 98171091088Posted: 2026-08-21Location: Belfast, Northern Ireland, United KingdomCategory: Technology, Applications Development, ProfessionalCompany: CitiSenior Software Engineer (Java Or Python) Engineer the future of global finance. At Citi, our Tech team doesn’t just support finance – we are helping to redefine it. Every day, $5 trillion crosses through our network. We do business in 180+ countries operating at a scale few can match. From deploying advanced AI to helping shape global markets, we build systems that matter. Look to join a team where your work helps influence economies, your ideas can drive innovation and outcomes, and your growth is backed by mentorship, continuous learning and flexibility with potential hybrid work opportunities. Help solve real-world challenges that touch millions and get the opportunity to build the future of finance with Citi Tech.Role Overview/What will you do:Partner with multiple management teams to ensure appropriate integration of functions to meet goals as well as identify and define necessary system enhancements to deploy new products and process improvementsResolve variety of high impact problems/projects through in-depth evaluation of complex business processes, system processes, and industry standardsProvide expertise in area and advanced knowledge of applications programming and ensure application design adheres to the overall architecture blueprintUtilize advanced knowledge of system flow and develop standards for coding, testing, debugging, and implementationDevelop comprehensive knowledge of how areas of business, such as architecture and infrastructure, integrate to accomplish business goalsProvide in-depth analysis with interpretive thinking to define issues and develop innovative solutionsServe as advisor or coach to mid-level developers and analysts, allocating work as necessaryAppropriately assess risk when business decisions are made, demonstrating particular consideration for the firm's reputation and safeguarding Citigroup, its clients and assets, by driving compliance with applicable laws, rules and regulations, adhering to Policy, applying sound ethical judgment regarding personal behavior, conduct and business practices, and escalating, managing and reporting control issues with transparency.Key Skills and Experience requiredAdditional Job DescriptionExperience in full‑stack application development with strong expertise in Java or Python Deep experience with backend frameworks such as Spring Boot / Spring Core and Flask / FastAPISolid frontend experience with modern JavaScript frameworks (React, Angular, or Vue)Experience designing and delivering scalable, cloud‑native applicationsExposure to Gen‑AI concepts including:Large Language Models (LLMs) and transformer‑based systemsPrompt engineering and basic agent workflowsVector search and retrieval conceptsFamiliarity with Gen‑AI frameworks/tools such as LangChain, LangGraph, MLflow, or workflow orchestration tools (e.g., n8n) (hands‑on experience preferred, but deep ML expertise not mandatory)Experience integrating Gen‑AI APIs (OpenAI, Gemini, Claude, etc.) into production applicationsFamiliarity with at least one major cloud provider (AWS, GCP, or Azure)This job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.What we’ll provide youBy joining Citi, you will not only be part of a business casual workplace with a hybrid working model (up to 2 days working at home per week), but also receive a competitive base salary (which is annually reviewed), and enjoy a whole host of additional benefits such as:27 days annual leave (plus bank holidays)A discretional annual performance related bonusPrivate Medical Care & Life InsuranceEmployee Assistance ProgramPension PlanPaid Parental LeaveSpecial discounts for employees, family, and friendsAccess to an array of learning and development resourcesVisit our About Us | Culture, Values & Benefits page to learn more.Alongside these benefits Citi is committed to ensuring our workplace is where everyone feels comfortable coming to work as their whole self, every day. We want the best talent around the world to be energized to join us, motivated to stay and empowered to thrive.#LI-AP2------------------------------------------------------Job Family Group: Technology------------------------------------------------------Job Family:Applications Development------------------------------------------------------Time Type:Full time------------------------------------------------------Most Relevant Skills Please see the requirements listed above.------------------------------------------------------Other Relevant Skills For complementary skills, please see above and/or contact the recruiter.------------------------------------------------------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 Accessibility at Citi.View Citi’s EEO Policy Statement and the Know Your Rights poster.