{"id":3070868,"url":"https://alion.io/job/citi-senior-low-latency-java-engineer","title":"Senior Low Latency Java Engineer","company":{"id":7841,"name":"Citi","domain":"citi.com","url":"https://alion.io/company/citi","size_band":"5000+","is_staffing_agency":false,"employer_type":"direct","is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"A","score":100,"open_postings":424,"ghost_share":0.007,"stale_share":0.071,"repost_share":0.085,"time_to_fill_p50_days":10,"computed_at":"2026-10-22T06:10:10Z"}},"role":"Backend","role_family":"Backend","seniority":"senior","employment_type":"full_time","work_mode":"hybrid","remote_scope":null,"remote_scope_basis":null,"remote_working_hours":null,"hiring_geo_confidence":"structured","locations":["London, United Kingdom"],"countries":["GB"],"hiring_countries":[],"hiring_countries_total":0,"salary":null,"salary_estimate":{"min_usd":85000,"max_usd":166000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":130},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"C++","optional":false},{"name":"Java","optional":false},{"name":"Linux","optional":false},{"name":"Matter","optional":false},{"name":"Time Series","optional":false},{"name":"UML","optional":false}],"status":"live","first_seen_at":"2026-10-14T00:00:00Z","employer_posted_date":"2026-10-14","last_verified_at":"2026-10-22T17:38:24Z","board_verified":true,"closed_at":null,"days_open":8,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":8},"description":"Senior Low Latency Java Engineer\nThis 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.\nThe 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.\nResponsibilities:\n70% 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.\nLead integration of functions to meet goals, deploy new products, and enhance processes\nAnalyze complex business processes, system processes, and industry standards to define and develop solutions to high level problems\nProvide world class expertise in area of Java low latency development.\nUtilize advanced knowledge of supported main system flows and comprehensive knowledge of multiple areas to achieve technology goals\nConsult with end users to identify system function specifications and incorporate into overall system design\nInfluence and negotiate with senior leaders and communicate with external parties\nAppropriately 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.\nHappy to work with and educate and support/mentor Junior developers and less experienced senior Java developers.\nSkills and Experience\nDemonstrated Subject Matter Expert (SME) in area(s) of Applications Development\nIn-depth experience with Algorithmic Trading application development, preferably in low latency environment\nDetailed comprehension and experience with Market Data handling and associated technologies (such as time-series databases e.g. KDB)\nDemonstrated leadership, project management, and development skills\nPassion for coding excellent, commercial grade, mission critical Java frameworks based on event sourcing microservices.\nComplete knowledge of modern Java, the JVM, the Linux Operating system, system calls and Kernel.\nKnowledge of TCP and other IP based network protocol technologies including hardware accelerated kernel bypass e.g. Solarflare OpenOnload\nPerformance assessment and targeted tuning.\nDesign and architectural elegance.\nExperience in implementing projects\nGreat communicator with high EQ.\nAbility to occasionally produce clear diagrammatic documentation and model key aspects in UML sequence diagrams.\nRelationship and consensus building skills\nNice to have\nBackground in C++\nEducation / Qualifications:\nBachelor’s degree/University degree or equivalent experience in a similar role.\n------------------------------------------------------\nJob Family Group:\nTechnology------------------------------------------------------\nJob Family:\nApplications Development------------------------------------------------------\nTime Type:\nFull time------------------------------------------------------\nMost Relevant Skills\nPlease see the requirements listed above.------------------------------------------------------\nOther Relevant Skills\nFor complementary skills, please see above and/or contact the recruiter.------------------------------------------------------\nCiti 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.\nIf 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.\nView Citi’s EEO Policy Statement and the Know Your Rights poster.","description_format":"text","description_chars":4648,"description_truncated":false,"requirements":{"experience_years_min":null,"management_years_min":null,"team_size_min":null,"manages_managers":false,"education":null,"security_clearance":false,"languages":[]},"benefits":[],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Cards & Card Issuing","Wealth Management & Financial Advisors","Payment Processing & Gateways","Investment Banking & M&A Advisory"],"lifecycle":[{"event":"open","at":"2026-10-22T09:24:37Z"}],"visa":[],"liveness":{"score":57,"band":"ok","label":"Likely open","p_open":1,"p_active":0.754,"p_room":0.75,"age_days":8,"expected_fill_days":10,"reasons":["conf:1","win:late","comp:brand"],"computed_at":"2026-10-22T18:59:52Z"},"pay":null,"html_url":"https://alion.io/job/citi-senior-low-latency-java-engineer","json_url":"https://alion.io/job/citi-senior-low-latency-java-engineer.json","meta":{"generated_at":"2026-10-22T18:59:52Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","about":"Alion is a live layer of people, companies and AI agents: who they are, whether they are 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