{"id":1157236,"url":"https://alion.io/job/citi-senior-software-engineer-ultra-low-latency-risk-engine-developer","title":"Senior Software Engineer – Ultra Low Latency Risk Engine Developer","company":{"id":7841,"name":"Citi","domain":"citi.com","url":"https://alion.io/company/citi","size_band":"5000+","is_staffing_agency":false,"is_intermediary":false,"listed_via":null,"ats_vendor":"Workday","truth_index":{"grade":"A","score":100,"open_postings":249,"ghost_share":0,"stale_share":0,"repost_share":0.08,"time_to_fill_p50_days":11,"computed_at":"2026-09-24T05:45:00Z"}},"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":83000,"max_usd":165000,"period":"year","method":"role_seniority_country_remote_cell","sample_n":87},"experience_years_min":null,"visa_sponsorship":false,"relocation_package":false,"has_equity":false,"technologies":[{"name":"Agile","optional":false},{"name":"C++","optional":false},{"name":"CI/CD","optional":false},{"name":"Java","optional":false},{"name":"Linux","optional":false},{"name":"Rust","optional":false},{"name":"Scrum","optional":false},{"name":"Shift-Left","optional":false},{"name":"Shift-Left Security","optional":false}],"status":"live","first_seen_at":"2026-09-23T22:01:45Z","employer_posted_date":"2026-09-23","last_verified_at":"2026-09-24T18:36:23Z","board_verified":true,"closed_at":null,"days_open":0,"trust":{"level":"ok","repost_count":null,"flags":[],"days_open":0},"description":"26996794 - Senior Software Engineer - Ultra Low Latency Risk Engine Developer\nOverview\nCiti Equities Technology | Equities Electronic Execution (Electronic Trading)\nCiti's Equities Technology organization is seeking a Senior Software Engineer - Ultra Low Latency Risk Engine Lead Developer to join the Equities Electronic Execution (Electronic Trading) technology team. This role is focused on the design, development, and delivery of Citi's next-generation low-latency Risk Engine for cash equities and its integration into the broader execution platform - encompassing the Centralised Position Service, Client Connectivity, Market Access layers, and high-throughput market data processing.\nRole Overview\nThe engineer will own critical, latency-sensitive risk-checking components that sit directly in the cash equities trading hot path, ensuring pre-trade and real-time risk controls are enforced with microsecond-level performance while maintaining correctness and resiliency at scale. This is a hands-on, deeply technical role that also carries leadership responsibilities - mentoring engineers, driving architecture decisions, and coordinating delivery across global development centers.\nThe person will collaborate closely with product development, quantitative research, technology infrastructure, production support, and QA teams, with close alignment to global strategy and cross-regional delivery (APAC, EMEA, NAM).\nRisk Engine & Core Development\nDesign, develop, and maintain the ultra-low-latency, in-line Risk Engine responsible for real-time pre-trade risk checks, position limits, and exposure controls across cash equities electronic execution flows.\nArchitect and optimize high-performance, lock-minimal, multi-threaded components capable of processing risk decisions in the sub-microsecond to low-microsecond range.\nIntegrate risk and position components with Client Connectivity, Market Access layers, and high-throughput market data feed handlers.\nDesign and implement low-latency messaging and IPC architectures using technologies such as Aeron and Solace, along with shared-memory/IPC mechanisms, to enable fast, reliable communication between distributed risk, execution, and position components.\nApply deep expertise in JVM performance tuning, memory management, garbage collection avoidance, and/or native (C++/Rust) performance engineering to eliminate latency outliers (\"jitter\") in the risk path.\nPerform system-level performance tuning including NUMA-aware application design and memory allocation, CPU core isolation/pinning and affinity tuning, interrupt/IRQ tuning, and kernel bypass or low-latency networking techniques (e.g., kernel bypass stacks, RDMA, solarflare/onload-style NIC tuning) to minimize end-to-end latency and jitter across the risk and execution path.\nProduct & Cross-Functional Collaboration\nPartner with cash equities traders, quantitative researchers, and clients to translate risk, exposure, and control requirements into robust engineering designs.\nWork with market access teams to ensure risk checks are correctly and efficiently embedded across order lifecycle events (new, amend, cancel) and multiple execution venues.\nSupport new liquidity source onboarding and DMA capability enhancements from a risk-controls perspective.\nTesting & Quality Engineering\nBuild and continuously improve deterministic, repeatable testing frameworks (unit, integration, latency/performance, and chaos/failover testing) tailored to ultra-low-latency risk systems.\nChampion test-driven development (TDD) practices for mission-critical, heavily multi-threaded, asynchronous components.\nEstablish performance benchmarking and latency regression testing - including messaging, network, CPU, and memory subsystem profiling - as part of the standard delivery pipeline.\nAI-Powered SDLC\nLeverage Citi's suite of AI-powered development tools across the SDLC to improve engineering productivity, code quality, and time-to-market for risk engine enhancements.\nAgile & CI/CD\nChampion Agile/Scrum practices and Rational Unified Process disciplines suited to complex, mission-critical trading systems.\nDrive CI/CD adoption with a shift-left testing philosophy, enabling accelerated, low-risk release cycles for latency-sensitive production systems.\nPlatform Support & Enhancement:\nBuild and maintain tooling for trading platform monitoring, real-time risk/position reconciliation, application recovery, and disaster-recovery/failover for the Risk Engine.\nProvide senior-level production support escalation for latency and risk-control incidents, including root-cause analysis of performance regressions across application, messaging, OS, and hardware layers.\nLeadership:\nLead and mentor a team of engineers across onshore/offshore locations and Drive architectural decisions and technical roadmap for the Risk Engine and related low-latency components, in alignment with global cash equities electronic trading strategy.\nKey Skills and Experience Required\nExtensive software engineering experience, with substantial hands-on experience building risk management, position-keeping, or other latency-critical systems for cash equities electronic trading or algorithmic trading platforms at a global investment bank or equivalent financial institution.\nStrong, hands-on technical expertise in Low Latency Java and/or C++ (Rust a plus), including multi-threading, concurrency, lock-free data structures, Java NIO, and JVM/GC performance tuning.\nHands-on experience with low-latency messaging and IPC frameworks such as Aeron, Solace, or equivalent shared-memory/IPC technologies for building distributed, high-throughput trading systems.\nDemonstrated background in real-time distributed risk management systems for cash equities flow products, including asynchronous, event-driven architectures.\nPractical, hands-on experience with NUMA-aware design, CPU core pinning/affinity and isolation, Linux kernel/OS tuning, and low-latency networking (kernel bypass, RDMA, or specialized NIC tuning) for ultra low-latency, high-throughput systems.\nStrong understanding of automated testing techniques, test-driven development, and quality engineering practices for mission-critical systems.\nSolid grounding in Agile/Scrum methodologies, Rational Unified Process, and Continuous Integration/Continuous Delivery pipelines.\nDeep familiarity with low-latency system design principles: performance optimization, concurrency, high-throughput architecture, and jitter elimination.\nDemonstrated leadership experience managing or technically leading engineering teams (onshore and/or offshore) delivering high-performance trading systems.\nExcellent communication skills, with the ability to present and grasp complex technical and risk concepts in a multicultural, cross-regional environment, and to work effectively with globally distributed stakeholders (trading desks, quants, infrastructure, and support teams).\nWorking knowledge of regional exchange microstructure and relevant regulatory regimes governing cash equities electronic trading and risk controls.\nThis job description provides a high-level review of the types of work performed. Other job-related duties may be assigned as required.\nWhat we’ll provide you\nBy 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:\n27 days annual leave (plus bank holidays)\nA discretional annual performance related bonus\nPrivate Medical Care & Life Insurance\nEmployee Assistance Program\nPension Plan\nPaid Parental Leave\nSpecial discounts for employees, family, and friends\nAccess to an array of learning and development resources\nVisit our Global Benefits page to learn more.\nAlongside 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.\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":9191,"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":["Annual leave","Hybrid work","Life insurance","Parental leave"],"hiring_locations":[{"name":"United Kingdom","iso":"GB","kind":"country"}],"hiring_excludes":[],"relocation_offered":false,"industries":["Wealth Management","Lending","Payments","Capital Markets"],"lifecycle":[{"event":"open","at":"2026-09-23T22:01:45Z"}],"liveness":{"score":90,"band":"hot","label":"Hiring now","p_open":1,"p_active":0.903,"p_room":1,"age_days":0,"expected_fill_days":11,"reasons":["conf:3","velocity","win:early","comp:brand"],"computed_at":"2026-09-24T05:45:00Z"},"pay":null,"html_url":"https://alion.io/job/citi-senior-software-engineer-ultra-low-latency-risk-engine-developer","json_url":"https://alion.io/job/citi-senior-software-engineer-ultra-low-latency-risk-engine-developer.json","meta":{"generated_at":"2026-09-24T21:44:41Z","cache_seconds":300,"methodology":"https://alion.io/methodology","terms":"https://alion.io/terms","contact":"https://alion.io/contact","api":"https://alion.io/developers","usage":{"tier":"crawler","counted_by":"subnet","units_charged":1,"used_today":49,"day_limit":5000,"remaining_today":4951,"minute_limit":60,"resets_at":"2026-09-25T00:00:00Z"}}}