Senior Low-Latency Risk Engine Engineer

Citi; Belfast City District; Hybrid; GBP 90,000 - 140,000; Full time

Benefits offered by this job

27 days annual leave

Discretionary annual bonus

Private medical care & life insurance

Employee assistance program

Pension plan

Paid parental leave

Discount programs

Job summary

Citi is seeking a Senior Software Engineer to design and deliver an ultra low-latency risk engine for cash equities, integrating with connectivity and data layers. You will own high-performance components, optimize JVM/C++ with low latency in mind, and collaborate across global teams to drive architecture and risk controls.

The role emphasizes mentorship, delivery across regions (APAC, EMEA, NAM), and a hands-on technical leadership style in a fast-paced trading environment.

Qualifications

• Proven software engineering experience in latency-critical systems for cash equities electronic trading or algorithmic trading platforms.
• Strong hands-on expertise in Low Latency Java and/or C++ (Rust a plus), including multi-threading and JVM/GC tuning.
• Experience with low-latency messaging/IPC frameworks (Aeron, Solace) for high-throughput trading systems.
• Background in real-time distributed risk management systems.
• Experience with NUMA-aware design, CPU core pinning/affinity and Linux tuning for ultra low-latency systems.
• Knowledge of automated testing techniques and quality engineering for mission-critical systems.
• Excellent communication in multicultural, cross-regional environments.

Responsibilities

• Design, develop, and maintain ultra low-latency risk engine for real-time pre-trade checks and exposure controls.
• Architect and optimize high-performance, multi-threaded components.
• Integrate risk/position components with connectivity and market data layers.
• Mentor engineers and drive architecture decisions across global teams.
• Ensure compliance with laws, policies and risk controls.

Skills

Low Latency Java/C++

Multithreading

Concurrency

Lock-free data structures

Java NIO

JVM/GC tuning

Real-time risk management

NUMA-aware design

CPU pinning/affinity

Linux kernel tuning

Low-latency networking

Aeron

Solace

Automated testing / TDD

Effective communication

Education

Bachelor’s degree/University degree or equivalent

Master’s degree preferred

Tools

Aeron

Solace

Linux

Job description

Citi is seeking a Senior Software Engineer to design and deliver an ultra low-latency risk engine for cash equities, integrating with connectivity and data layers. You will own high-performance components, optimize JVM/C++ with low latency in mind, and collaborate across global teams to drive architecture and risk controls.

The role emphasizes mentorship, delivery across regions (APAC, EMEA, NAM), and a hands-on technical leadership style in a fast-paced trading environment.