Senior Low-Latency Java Engineer — Algo Trading

Citi; Greater London; On-site; GBP 120,000 - 180,000; Full time

Job summary

Citi in London is seeking a Senior Low Latency Java Engineer to lead development of high-performance trading applications and frameworks. The role sits in the HPA team, focusing on Java-based microservices and low-latency design across Citi’s trading platforms.

You will work with market data handling, time-series databases like KDB, and mentor junior developers while collaborating with senior stakeholders to modernise and optimise the trading infrastructure.

Qualifications

• Bachelor's degree or equivalent required.
• Senior level with extensive low-latency experience.
• Experience in algorithmic trading and market data handling.
• Strong leadership and collaboration skills.
• Proven Java low-latency development expertise and microservices.
• Deep knowledge of Java/JVM and Linux.
• Familiarity with TCP/IP and kernel bypass.
• Ability to analyze complex processes and design scalable solutions.

Responsibilities

• Hands-on Java development in a low-latency environment (70% of time).
• Lead integration of functions to meet goals and deploy new products.
• Analyze complex business and system processes to define solutions.
• Provide expertise in Java low-latency development.
• Consult with end users to capture specifications and inform design.
• Influence senior leaders and liaise with external parties.
• Assess risk and ensure compliance with policies and regulations; escalate as needed.
• Mentor junior developers and support/coach peers.

Skills

SME in Applications Development

Algorithmic Trading (low latency)

Market Data handling (KDB)

Leadership & project management

Java low-latency frameworks

Java, JVM, Linux

TCP/IP & kernel bypass (OpenOnload)

Performance tuning

Architecture/design

UML diagrams

Communication & EQ

Mentoring juniors

C++ (nice to have)

Education

Bachelor's degree

Tools

C++

Job description

Citi in London is seeking a Senior Low Latency Java Engineer to lead development of high-performance trading applications and frameworks. The role sits in the HPA team, focusing on Java-based microservices and low-latency design across Citi’s trading platforms.

You will work with market data handling, time-series databases like KDB, and mentor junior developers while collaborating with senior stakeholders to modernise and optimise the trading infrastructure.