207294-1 - Senior Java Developer

Skillfinder International; Greater London; Hybrid; GBP 90,000 - 130,000; Full time

Job summary

Skillfinder International is seeking a Java Developer to join a low-latency trading systems team in London. You will design and build high-performance Java applications, optimise memory and CPU usage, and contribute to a platform serving EMEA and US markets.

Candidates should have deep JVM tuning, concurrency and memory management expertise, and hands-on experience with event-driven or reactive architectures. Familiarity with Linux internals and low-level Java tech like JNI or Unsafe is a plus.

Qualifications

• Strong Java development experience focused on low-latency, high-performance systems.
• Hands-on expertise in JVM tuning and garbage collection optimisation.
• Excellent understanding of data structures, algorithms and concurrent programming.
• Experience developing event-driven or reactive systems operating at high frequency.
• Knowledge of native interoperability and low-level Java technologies, such as JNI, Java Unsafe and JNR-FFI.
• Strong understanding of CPU architecture, memory management and Linux internals.
• Experience with shared memory and memory-mapped files.
• Strong knowledge of networking protocols, particularly TCP and UDP.

Responsibilities

• Design, develop and optimise high-performance Java applications supporting trading and liquidity services.
• Build and enhance low-latency, event-driven and reactive systems.
• Tune JVM performance and garbage collection to improve throughput and reduce latency.
• Investigate and resolve performance bottlenecks across application, memory and networking layers.
• Develop efficient concurrent processing and inter-process communication solutions.
• Collaborate with technical and business teams to deliver projects across EMEA and the US.

Skills

Java

Low-latency

JVM tuning

Concurrency

Event-driven

JNI/Unsafe

Linux

Networking

Memory management

Performance

Tools

Aeron

Job description

Java Developer – Low-Latency Trading Systems

Location: London
Working arrangement: Hybrid – 3 days per week in the office

We are looking for a Java Developer with strong experience building low-latency, high-performance systems to support the expansion of an agency liquidity platform and delivery of projects across EMEA and the US.

The role requires deep Java expertise, including JVM tuning, concurrency and memory management, alongside experience developing event-driven systems operating at high frequency.

Key Responsibilities

• Design, develop and optimise high-performance Java applications supporting trading and liquidity services.
• Build and enhance low-latency, event-driven and reactive systems.
• Tune JVM performance and garbage collection to improve throughput and reduce latency.
• Investigate and resolve performance bottlenecks across application, memory and networking layers.
• Develop efficient concurrent processing and inter-process communication solutions.
• Collaborate with technical and business teams to deliver projects across EMEA and the US.

Essential Skills & Experience

• Strong Java development experience focused on low-latency, high-performance systems.
• Hands-on expertise in JVM tuning and garbage collection optimisation.
• Excellent understanding of data structures, algorithms and concurrent programming.
• Experience developing event-driven or reactive systems operating at high frequency.
• Knowledge of native interoperability and low-level Java technologies, such as JNI, Java Unsafe and JNR-FFI.
• Strong understanding of CPU architecture, memory management and Linux internals.
• Experience with shared memory and memory-mapped files.
• Strong knowledge of networking protocols, particularly TCP and UDP.

Desirable Skills

• Experience with Aeron.
• Previous experience developing trading or liquidity platforms.