Discover your future at Citi
Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you'll have the opportunity to grow your career, give back to your community and make a real impact.
Job Overview
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. 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.
About the Position
We are looking for an industry‑wide Senior Systems Architect (Infrastructure) who can provide leadership and direction for Change‑The‑Bank (CTB) electronic trading infrastructure initiatives covering all technologies for Rates. The role sits within Citi’s Global Markets: High Performance Architectures – Infrastructure (HPAi) group. This team is responsible for all electronic trading infrastructure architecture across all markets globally for the firm. It is composed of low latency subject matter experts, systems architects and an aligned initiative management function. Technology is key to our business; this role will require you to drive innovation and technology adoption in a large, multi‑faceted and complex environment.
What You Will Do (but Not Limited To)
Reporting to the head of HPAi, the Systems Architect will be responsible for ensuring best‑in‑breed technology architecture and engineering are in alignment with business requirements. This will be done in collaboration with the relevant teams and stakeholders. You will actively collaborate with all parties, steer other technology organizations directly or through influence, and love rolling up your sleeves and working as an individual contributor.
The Technologies
- Compute (Linux, CoreOS, Tuning, kernel bypass technologies, core dump analysis)
- Network (R&S, cut‑through, Multicast, SDN, BGP, L1‑L3, PCAP analysis)
- HPC File Systems (Lustre, GPFS, Weka, DDN, Ceph)
- Interconnects (InfiniBand, Slingshot, PCIe, NVLink, UALink, UPI, RoCE)
- HW (Server, FPGA, GPU, Memory, Cache, over‑clocking, cooling, ASIC, Quantum, NUMA)
- DevOps (OpenShift, Kubernetes, CI/CD, Python, Perl, Shell)
- Programming (C, C++, Java, Rust, VHDL, Verilog)
- Time Sync (PTP, NTP, GPS, White Rabbit, SyncE)
- Wave (RF, Millimeter, Microwave, DWDM, Photonics)
- Storage (I/O, NAS, SAN, Object Store, SDS)
- Database (relational, columnar, graph, NoSQL, architecture, tuning)
- Monitoring (SPANs, TAPS, OEO, Packet Brokers, Corvil, SNMP, FIX, Logs, ELK, Open Telemetry, Grafana, Prometheus)
- Messaging (TibRV, Solace, Aeron, ZeroMQ, Kafka, Multicast, Market data, Tibco, Exegy/Vela)
- Load Balancers (HW, SW)
- Security (Firewalls, PKI, TLS, IDS, Optical Encryption, AD, LDAP)
- Connectivity (WAN, Lucera, cross‑connects, ECX, venue, client)
- Colo / Datacenter (Power, Space, Cage, Rack, Cabinet, Design)
- Excel (for advanced frameworks, data analysis)
Required
- Deep knowledge of operating system fundamentals – hyper focus on Linux (REL, CoreOS)
- Understanding of OSI model and TCP/UDP network protocols
- Experience with Python and data libraries
- Fluency with the Unix command line and shell scripting
- Practical experience with modern Linux systems and systems programming concepts like C, IPC mechanisms, virtual memory, and process life cycle
- Strong troubleshooting skills and knowledge of profiling/debugging tools such as gdb, perf, DTrace, SystemTap
- Can understand, interpret, and improve application performance via system tuning
- Thorough understanding of modern computer architecture – modern x86, AMD and Intel cache hierarchies as an example
- Kernel‑bypass technology knowledge (such as Solarflare OpenOnload / TCPDirect / ef_vi, RoCE, DPDK)
- Prior experience in a similar Site Reliability Engineering, DevOps, distributed computing, systems engineering/administration
- Ability to context‑switch to work on several projects at once
- Knowledge of JIRA, SCRUM, Sprints
- Low Latency Trading – Rates and Cross Markets domain knowledge would be highly beneficial
The Details
- Ingress/plan/execute/manage technical initiatives to make our electronic trading systems faster, more adaptable, stable and maintainable aligned to HPAi standards
- Communicate ideas, requirements, and results across disparate teams
- This position will support technical populations (Rates), partnering with leaders to understand their challenges and design and execute solutions to solve them
- Communicate business and IT requirements to external vendors and internal technical teams
- To succeed in this role, you must enjoy working independently and collaborating, being a hands‑on contributor, learning on the fly and embrace change – rapid pace
- You must be able to understand full‑stack electronic trading technologies and engage effectively in a very technical manner with other SMEs, systems architects, the business (at times), Markets‑Tech, and enterprise infrastructure organizations (CTI/CISO)
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 discretionary 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.
Education
Degree educated ideally in a computer science or engineering field or experience operating 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. 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.
#J-18808-Ljbffr”, “datePosted”: “2026-05-18”, “hiringOrganization”: { “@type”: “Organization”, “name”: “Jobs via eFinancialCareers”, “sameAs”: “https://uk.whatjobs.com/pub_api__cpl__435628584__4861?utm_campaign=publisher&utm_medium=api&utm_source=4861&geoID=33” }, “jobLocation”: { “@type”: “Place”, “address”: { “@type”: “PostalAddress”, “addressLocality”: “London” } } }Discover your future at Citi
Working at Citi is far more than just a job. A career with us means joining a team of more than 230,000 dedicated people from around the globe. At Citi, you’ll have the opportunity to grow your career, give back to your community and make a real impact.
Job Overview
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. 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.
About the Position
We are looking for an industry‑wide Senior Systems Architect (Infrastructure) who can provide leadership and direction for Change‑The‑Bank (CTB) electronic trading infrastructure initiatives covering all technologies for Rates. The role sits within Citi’s Global Markets: High Performance Architectures – Infrastructure (HPAi) group. This team is responsible for all electronic trading infrastructure architecture across all markets globally for the firm. It is composed of low latency subject matter experts, systems architects and an aligned initiative management function. Technology is key to our business; this role will require you to drive innovation and technology adoption in a large, multi‑faceted and complex environment.
What You Will Do (but Not Limited To)
Reporting to the head of HPAi, the Systems Architect will be responsible for ensuring best‑in‑breed technology architecture and engineering are in alignment with business requirements. This will be done in collaboration with the relevant teams and stakeholders. You will actively collaborate with all parties, steer other technology organizations directly or through influence, and love rolling up your sleeves and working as an individual contributor.
The Technologies
- Compute (Linux, CoreOS, Tuning, kernel bypass technologies, core dump analysis)
- Network (R&S, cut‑through, Multicast, SDN, BGP, L1‑L3, PCAP analysis)
- HPC File Systems (Lustre, GPFS, Weka, DDN, Ceph)
- Interconnects (InfiniBand, Slingshot, PCIe, NVLink, UALink, UPI, RoCE)
- HW (Server, FPGA, GPU, Memory, Cache, over‑clocking, cooling, ASIC, Quantum, NUMA)
- DevOps (OpenShift, Kubernetes, CI/CD, Python, Perl, Shell)
- Programming (C, C++, Java, Rust, VHDL, Verilog)
- Time Sync (PTP, NTP, GPS, White Rabbit, SyncE)
- Wave (RF, Millimeter, Microwave, DWDM, Photonics)
- Storage (I/O, NAS, SAN, Object Store, SDS)
- Database (relational, columnar, graph, NoSQL, architecture, tuning)
- Monitoring (SPANs, TAPS, OEO, Packet Brokers, Corvil, SNMP, FIX, Logs, ELK, Open Telemetry, Grafana, Prometheus)
- Messaging (TibRV, Solace, Aeron, ZeroMQ, Kafka, Multicast, Market data, Tibco, Exegy/Vela)
- Load Balancers (HW, SW)
- Security (Firewalls, PKI, TLS, IDS, Optical Encryption, AD, LDAP)
- Connectivity (WAN, Lucera, cross‑connects, ECX, venue, client)
- Colo / Datacenter (Power, Space, Cage, Rack, Cabinet, Design)
- Excel (for advanced frameworks, data analysis)
Required
- Deep knowledge of operating system fundamentals – hyper focus on Linux (REL, CoreOS)
- Understanding of OSI model and TCP/UDP network protocols
- Experience with Python and data libraries
- Fluency with the Unix command line and shell scripting
- Practical experience with modern Linux systems and systems programming concepts like C, IPC mechanisms, virtual memory, and process life cycle
- Strong troubleshooting skills and knowledge of profiling/debugging tools such as gdb, perf, DTrace, SystemTap
- Can understand, interpret, and improve application performance via system tuning
- Thorough understanding of modern computer architecture – modern x86, AMD and Intel cache hierarchies as an example
- Kernel‑bypass technology knowledge (such as Solarflare OpenOnload / TCPDirect / ef_vi, RoCE, DPDK)
- Prior experience in a similar Site Reliability Engineering, DevOps, distributed computing, systems engineering/administration
- Ability to context‑switch to work on several projects at once
- Knowledge of JIRA, SCRUM, Sprints
- Low Latency Trading – Rates and Cross Markets domain knowledge would be highly beneficial
The Details
- Ingress/plan/execute/manage technical initiatives to make our electronic trading systems faster, more adaptable, stable and maintainable aligned to HPAi standards
- Communicate ideas, requirements, and results across disparate teams
- This position will support technical populations (Rates), partnering with leaders to understand their challenges and design and execute solutions to solve them
- Communicate business and IT requirements to external vendors and internal technical teams
- To succeed in this role, you must enjoy working independently and collaborating, being a hands‑on contributor, learning on the fly and embrace change – rapid pace
- You must be able to understand full‑stack electronic trading technologies and engage effectively in a very technical manner with other SMEs, systems architects, the business (at times), Markets‑Tech, and enterprise infrastructure organizations (CTI/CISO)
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 discretionary 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.
Education
Degree educated ideally in a computer science or engineering field or experience operating 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. 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.
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