Java Low Latency Engineer

Role: Java Low Latency Engineer / Java Performance Engineer

Location: London / Hybrid - 3 days in London office

Day rate: DoE

Sector: Wealth Management, Investment Banking, Asset Management, Personal & Corporate Banking

We are seeking an experienced Java Low Latency Engineer / Java Performance Engineer to join a high-performing engineering team responsible for building and optimising mission-critical, event-driven systems operating in ultra-low latency environments.

You will work on the design, development, and optimisation of high-throughput, high-frequency systems where performance, scalability, and reliability are paramount. This role requires a deep understanding of JVM internals, concurrency, networking, memory management, and Linux-based performance tuning.

Key Responsibilities

• Design and develop high-performance Java applications for low-latency environments.

• Optimise JVM performance through advanced tuning, profiling, and troubleshooting.

• Build resilient, event-driven and reactive systems capable of handling high transaction volumes.

• Analyse and improve system performance across application, JVM, operating system, and hardware layers.

• Implement efficient concurrency models and low-latency messaging solutions.

• Work closely with architecture and infrastructure teams to deliver scalable, production-ready solutions.

• Conduct performance testing, benchmarking, and capacity planning.

• Investigate and resolve latency bottlenecks across distributed systems.

Essential Skills & Experience

• Expert-level Java development experience.

• Proven experience with JVM performance tuning and optimisation.

• Strong understanding of Data Structures and Algorithms.

• Experience developing low latency, high throughput, event-driven systems.

• Extensive knowledge of:

• Concurrency and multithreading

• Garbage Collection (GC)

• JNI (Java Native Interface)

• Java Unsafe

• JNR-FFI

• Experience building systems that operate within demanding latency constraints.

Must Have Experience:

• ✅ Strong Core Java Development

• ✅ JVM Performance Tuning

• ✅ Low Latency / High Performance Systems

• ✅ Concurrency & Multithreading

• ✅ Data Structures & Algorithms

• ✅ Networking

• ✅ Linux

Nice to Have

• Experience with Aeron messaging framework.

• Exposure to financial trading, market data, or high-frequency systems.

• Knowledge of distributed systems and messaging technologies.

• Familiarity with modern observability and monitoring platforms