Low Latency Java Engineer

Overview

In this senior role, you will lead low-latency Java-based engineering within Citi’s London High Performance Architectures team, delivering fast, mission-critical frameworks for algorithmic trading. You will shape and implement scalable, event-sourced microservices and work closely with cross-functional experts to meet performance goals. You’ll mentor junior engineers while collaborating with senior leaders to align technology with trading and market data objectives. This opportunity combines high-impact systems work with ongoing learning, mentorship, and hybrid work options, offering a clear path to influence global finance. You will help build and modernize core trading platforms that touch

Pay / Benefits

• hybrid working model (up to 2 days home)
• 27 days annual leave plus bank holidays
• discretionary annual bonus
• Private Medical Care & Life Insurance
• Employee Assistance Program
• Pension Plan

Responsibilities

• Hands-on development in Java or Rust within a low-latency, event-sourced microservices framework
• Lead integration and deployment of new products and process improvements
• Analyse complex business and system processes to design robust solutions
• Provide expert Java low-latency development guidance across supported system flows
• Consult with end users to translate function specifications into design
• Mentor junior developers and less experienced engineers
• Collaborate with senior leaders and external stakeholders to influence direction

Key requirements

• Subject Matter Expert in Applications Development
• Experience in Algorithmic Trading application development in a low-latency environment
• Strong knowledge of Market Data handling and time-series databases like KDB
• Leadership, project management, and development skills
• Proficiency in modern Java, JVM, Linux, system calls, and kernel concepts
• Knowledge of TCP/IP networking and kernel bypass technologies (Solarflare OpenOnload)
• Performance tuning and architectural design
• Good communication and diagramming skills (UML)
• Nice to have: C++ background

• Great communicator with high EQ
• ability to mentor others
• relationship and consensus building skills
• Java low-latency development
• Algorithmic trading systems
• Market data handling and KDB