Senior Low Latency Engineer (London)

About the role

Citi is looking for a Senior Low Latency Engineer to join its High Performance Architectures (HPA) team in London. You will work on mission‑critical trading systems that process billions of dollars in transactions daily, building ultra‑fast micro‑services and event‑sourcing frameworks.

Key responsibilities

• Design, develop, and maintain low‑latency Java and Rust codebases for algorithmic trading utilities.
• Build and optimise micro‑service components that achieve response times between 10 µs and 100 µs.
• Lead integration of new functionalities, deploy products, and enhance existing processes.
• Collaborate with subject‑matter experts to provide application frameworks for over 100 internal teams.
• Analyse complex business and system processes to deliver high‑performance solutions.

Required profile

• Proven senior‑level experience in low‑latency systems engineering.
• Strong background in financial markets technology, especially e‑trading platforms.
• Ability to work independently and mentor junior engineers.

Required skills

• Java
• C++
• Rust
• KDB
• Market data handling
• Algorithmic trading technology
• Microservices architecture
• Event sourcing

What we offer

• Hybrid work model with flexibility.
• Mentorship, continuous learning, and career growth opportunities.
• Exposure to global finance infrastructure handling $5 trillion daily.