Low Latency Java Engineer (VP)

Overview

As a Senior Low Latency Java Engineer at Citi, you will help build and optimize high-performance trading systems within the London-based High Performance Architectures team. You will contribute to Java and Rust code, microservices, and in-house low-latency frameworks to process market data with ultra-fast response times. You will mentor junior developers, influence senior stakeholders, and collaborate across cross-functional teams to enable application modernization. This is a mission-driven role at scale, shaping the future of electronic trading in global markets. You will work in a flexible, mentorship‑backed environment with opportunities for hybrid work and continuous learning.

Pay / Benefits

• 27 days annual leave (plus bank holidays)
• Discretionary annual bonus
• Private Medical Care & Life Insurance
• Employee Assistance Program
• Pension Plan
• Paid Parental Leave

Responsibilities

• Hands-on development in Java or Rust within a low-latency microservices/event-sourcing framework
• Lead integration of functions to meet goals and deploy new products
• Analyze complex business and system processes to design high-level solutions
• Provide expertise in Java low-latency development
• Consult with end users to capture system requirements and translate into design
• Influence senior leaders and communicate with external parties
• Mentor junior developers and less experienced senior Java developers
• Support and educate peers on market data handling and back-test utilities

Key requirements

• Subject Matter Expert in Applications Development
• Experience in algorithmic trading application development in a low-latency environment
• Knowledge of Market Data handling and time-series databases (e.g. KDB)
• Leadership, project management and development skills
• Strong Java expertise, JVM, Linux, system calls, and kernel knowledge
• TCP/IP and network protocol knowledge including hardware-accelerated kernel bypass (e.g. Solarflare OpenOnload)
• Performance assessment and tuning
• Strong design and architectural sense
• Clear communication and relationship-building skills
• UML diagramming ability
• Nice to have: C++ background

• Strong communication with high EQ
• ability to mentor and educate peers
• relationship and consensus-building skills
• Java low-latency development
• JVM and Linux system knowledge
• Market Data handling and time-series databases (e.g. KDB)