Senior Ultra-Low Latency Risk Engine Lead

Citi; Greater London; Hybrid; GBP 120,000 - 160,000; Full time

Benefits offered by this job

27 days annual leave

Discretional annual bonus

Private medical care & life insurance

Employee assistance program

Pension plan

Paid parental leave

Learning and development resources

Job summary

Citi Equities Technology in London is seeking a Senior Software Engineer to own the ultra-low-latency risk engine in the cash equities trading hot path, with leadership responsibilities inspiring a distributed team.

You will design, implement, and tune multi-threaded components, apply JVM or native performance techniques, and collaborate with traders, researchers, and QA across regions to deliver low-latency risk checks and real-time controls.

Qualifications

• Extensive software engineering experience in latency-sensitive trading systems.
• Strong hands-on expertise in Java and/or C++ with low-latency focus.
• Experience with Aeron, Solace or equivalent IPC frameworks.
• Background in NUMA-aware design and kernel/OS tuning.
• Leadership experience managing engineering teams (onshore/offshore).

Responsibilities

• Design, develop, and maintain the ultra-low-latency risk engine for real-time checks.
• Lead and mentor engineers across locations, drive architecture decisions.
• Collaborate with traders, quants, infra, and QA across regions.
• Implement testing frameworks for latency and performance, CI/CD.
• Optimize end-to-end latency with advanced hardware and software techniques.

Skills

Ultra-low latency

Java (Low Latency)

C++/Rust

Multithreading

JVM/GC tuning

Aeron

Solace

IPC/Shared memory

Leadership

Performance optimization

Education

Bachelor’s or higher in CS/Engineering

Tools

Aeron

Solace

Linux kernel tuning

RDMA / kernel bypass

Job description

Citi Equities Technology in London is seeking a Senior Software Engineer to own the ultra-low-latency risk engine in the cash equities trading hot path, with leadership responsibilities inspiring a distributed team.

You will design, implement, and tune multi-threaded components, apply JVM or native performance techniques, and collaborate with traders, researchers, and QA across regions to deliver low-latency risk checks and real-time controls.