Senior Low Latency Engineer
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.
What We do / The Team
This 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++ , Rust, 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 organization 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 include (but not limited to):
- 90% hands in the Java or Rust 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 processes
- Analyse complex business processes, system processes, and industry standards to define and develop solutions to high level problems
- Provide 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 goals
- Consult with end users to identify system function specifications and incorporate into overall system design
- Influence and negotiate with senior leaders and communicate with external parties
- Happy to work with and educate and support/mentor Junior developers and less experienced senior Java developers.
Key Skills and Experience required
- Demonstrated Subject Matter Expert (SME) in area(s) of Applications Development
- In-depth experience with Algorithmic Trading application development, preferably in low latency environment
- Detailed comprehension and experience with Market Data handling and associated technologies (such as time-series databases e.g. KDB)
- Demonstrated leadership, project management, and development skills
- Passion 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 OpenOnload
- Performance assessment and targeted tuning.
- Design and architectural elegance.
- Experience in implementing projects
- Great communicator with high EQ.
- Ability to occasionally produce clear diagrammatic documentation and model key aspects in UML sequence diagrams.
- Relationship and consensus building skills
Nice to have
- Background in C++
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 you
By 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 bonus
- Private Medical Care & Life Insurance
- Employee Assistance Program
- Pension Plan
- Paid Parental Leave
- Special discounts for employees, family, and friends
- Access to an array of learning and development resources
Visit 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
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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.
Skills Required
- Demonstrated Subject Matter Expert in Applications Development
- In-depth experience with Algorithmic Trading application development in low latency environments
- Detailed comprehension and experience with Market Data technologies including time-series databases like KDB
- Demonstrated leadership and project management skills
- Passion for coding mission critical Java frameworks based on event sourcing
- Complete knowledge of modern Java, the JVM, and Linux OS
- Knowledge of TCP and IP based network protocols including hardware accelerated kernel bypass
- Experience in implementing projects
Citi Compensation & Benefits Highlights
The following summarizes recurring compensation and benefits themes identified from responses generated by popular LLMs to common candidate questions about Citi and has not been reviewed or approved by Citi.
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Healthcare Strength — Benefits coverage is positioned as comprehensive, including health, dental, and vision insurance plus on-site clinics, prescription drug support, and disability coverage. Family-building support such as fertility assistance is described as a notable differentiator within the overall package.
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Retirement Support — Retirement benefits are framed as strong, highlighted by a 401(k) with matching and additional plan options like a Roth 401(k). Financial support is reinforced through discounts and broader financial guidance resources tied to the benefits ecosystem.
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Wellbeing & Lifestyle Benefits — Wellbeing support extends beyond insurance through programs like an Employee Assistance Program, counseling/legal resources, and gym or wellness reimbursement. These offerings increase the perceived total rewards value even when cash compensation sentiment varies by role.
Citi Insights
What We Do
Citi's mission is to serve as a trusted partner to our clients by responsibly providing financial services that enable growth and economic progress. Our core activities are safeguarding assets, lending money, making payments and accessing the capital markets on behalf of our clients. We have 200 years of experience helping our clients meet the world's toughest challenges and embrace its greatest opportunities. We are Citi, the global bank – an institution connecting millions of people across hundreds of countries and cities.
