Low Latency Java Engineer
Summary
Senior engineer on Citi's London High Performance Architectures team building low-latency, event-sourced microservices for algorithmic trading. Day to day: hands-on Java (or Rust) low-latency development, performance tuning, integrating new trading products, and mentoring junior engineers; hybrid role, up to 2 days from home.
In this senior role, you will design and implement high-performance, low-latency applications within Citi’s London HPA team that enable rapid market decisions. You will work on algorithmic trading infrastructure, contribute to modernisation efforts, and mentor peers while collaborating with senior leaders across the bank. Your work will touch real-time data, microservices, and in-house frameworks to support global markets. This is an opportunity to influence trading systems at scale and advance low-latency tech across Citi.
Pay / Benefits- Hybrid working model (up to 2 days remote)
- 27 days annual leave + bank holidays
- Discretionary annual performance bonus
- Private medical care & life insurance
- Employee assistance program
- Pension plan
- Hands-on development in Java or Rust, focusing on low-latency code and microservices-based event sourcing systems
- Lead integration of functions to meet goals, deploy new products, and improve processes
- Analyse complex business and system processes to define solutions for high-level problems
- Provide deep expertise in Java low-latency development and main system flows
- Leverage broad system knowledge to achieve technology goals and advisor users on design
- Mentor junior developers and less experienced seniors, and collaborate with stakeholders
- Consult with end users to translate requirements into system designs
- Communicate with senior leaders and external parties to influence decisions
- Support performance tuning and architectural design for low-latency trading platforms
- Foster application modernization efforts across Citi’s teams
- SME in Applications Development
- Experience in Algorithmic Trading in a low-latency environment
- Market data handling experience including time-series databases (e.g., KDB)
- Leadership, project management, and development skills
- Strong Java skills, JVM, Linux, system calls and kernel knowledge
- TCP/IP networking knowledge and kernel bypass technologies (e.g., Solarflare OpenOnload)
- Performance assessment and targeted tuning
- Ability to document diagrams and UML models
- Excellent communication and consensus-building abilities
- Nice to have: C++ background
- Strong communication with high EQ
- Mentorship and coaching mindset
- Relationship and consensus-building
- Java low-latency development
- Algorithmic trading systems
- Market data handling and KDB