Job ID: 101956603216Posted: 2026-10-14Location: London, England, United KingdomCategory: Technology, Applications Development, ProfessionalCompany: CitiSenior Low Latency Java EngineerThis is a senior level position responsible for establishing and implementing new or revised application systems and programs in coordination with the Technology Team. The overall objective of this role is to lead applications systems analysis and programming activities.
The role is to provide senior, low-latency systems and application framework engineering (skilled in Java, C++, KDB, market data, algorithmic trading technology) within the London Based High Performance Architectures (HPA ) team. The team require a specialist on algorithmic trading systems utilities including but not limited to market data replay and back test/simulation utilities. The HPA organisation are a high skilled enablement group of Subject Matter experts - who produce application frameworks and engage with application engineers to enable application Modernisation to over 100 teams across Citi with a concentration on low latency eTrading platforms in Markets Technology.
Responsibilities:
70% hands in the Java codebase. We build microservices based event sourcing systems on a low latency in-house framework. Response times in the 10 microsecond to 100 microsecond range.
Lead integration of functions to meet goals, deploy new products, and enhance processesAnalyze complex business processes, system processes, and industry standards to define and develop solutions to high level problemsProvide world class expertise in area of Java low latency development.
Utilize advanced knowledge of supported main system flows and comprehensive knowledge of multiple areas to achieve technology goalsConsult with end users to identify system function specifications and incorporate into overall system designInfluence and negotiate with senior leaders and communicate with external partiesAppropriately 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 behaviour, conduct and business practices, and escalating, managing and reporting control issues with transparency.
Happy to work with and educate and support/mentor Junior developers and less experienced senior Java developers.
Skills and ExperienceDemonstrated Subject Matter Expert (SME) in area(s) of Applications DevelopmentIn-depth experience with Algorithmic Trading application development, preferably in low latency environmentDetailed comprehension and experience with Market Data handling and associated technologies (such as time-series databases e.g. KDB)Demonstrated leadership, project management, and development skillsPassion for coding excellent, commercial grade, mission critical Java frameworks based on event sourcing microservices.
Complete knowledge of modern Java, the JVM, the Linux Operating system, system calls and Kernel.
Knowledge of TCP and other IP based network protocol technologies including hardware accelerated kernel bypass e.g. Solarflare OpenOnloadPerformance assessment and targeted tuning.
Design and architectural elegance.
Experience in implementing projectsGreat communicator with high EQ.Ability to occasionally produce clear diagrammatic documentation and model key aspects in UML sequence diagrams.
Relationship and consensus building skillsNice to haveBackground in C++Education / Qualifications: Bachelor's degree/University degree or equivalent experience in a similar role.------------------------------------------------------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.
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Senior Low Latency Java Engineer in London employer: Citigroup
Citi is an exceptional employer, offering a dynamic work environment in the heart of London where innovation meets collaboration. As a Sales Director, you will benefit from extensive training and mentorship opportunities, fostering your professional growth while working alongside industry leaders in FX Sales. With a strong commitment to integrity and inclusivity, Citi provides a supportive culture that empowers employees to excel and drive meaningful results for clients.
