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
