Low Latency Java Developer

Luxoft; Greater London; On-site; GBP 90,000 - 130,000; Full time

Job summary

Luxoft is seeking a Senior Java Engineer to join a global technology team delivering high-throughput, low-latency platforms. You will work on event-driven systems near the JVM, Linux, and network stack to optimise real-time data processing.

You will design and optimise core Java applications, perform JVM profiling and memory analysis, and contribute to low-latency networking. The role requires deep multithreading knowledge and experience with JNI/Java Unsafe.

Qualifications

• Strong experience in JVM tuning and performance engineering.
• Deep knowledge of multithreading, concurrency, data structures and algorithms.
• Proven track record building high-throughput, event-driven and reactive systems.
• Experience with Linux performance analysis and optimisation.

Responsibilities

• Designing and developing high-performance Java applications using Core Java.
• Building scalable event-driven and reactive architectures.
• Performing JVM profiling, GC tuning, memory analysis, and latency optimisation.
• Optimising multithreaded applications and concurrent processing frameworks.
• Enhancing network performance using TCP/UDP and low-latency techniques.
• Working with JNI, Java Unsafe and native integrations.

Skills

JVM tuning

Performance engineering

Multithreading

Concurrency

Data structures

Algorithms

Event-driven design

Reactive applications

Networking performance

Tools

JNI

Java Unsafe

JNR-FFI

Job description

We're looking for a Senior Java Engineer with a passion for performance engineering to join a global technology team delivering some of the industry's most demanding high-throughput, low-latency platforms. This is an opportunity to work on sophisticated event-driven systems where microseconds matter. You'll be operating close to the JVM, Linux operating system, network stack, and hardware layer, helping build and optimise applications that process massive volumes of real-time data with exceptional speed and reliability.

If you enjoy solving complex performance challenges and pushing Java beyond traditional enterprise development, you will have fun here.

What You'll Be Doing

• Designing and developing high-performance applications using Core Java
• Building scalable event-driven and reactive architectures
• Performing JVM profiling, GC tuning, memory analysis, and latency optimisation
• Optimising multithreaded applications and concurrent processing frameworks
• Enhancing network performance using TCP/UDP and low-latency communication techniques
• Working with low-level Java technologies including JNI, Java Unsafe and native integrations
• Identifying bottlenecks across Linux, JVM and application layers

What We're Looking For

• Strong JVM tuning and performance engineering experience
• Deep understanding of:
  • Multithreading
  • Concurrency
  • Data structures
  • Algorithms
  • Computational complexity
• Proven experience building:
  • High-throughput platforms
  • Event-driven architectures
  • Reactive applications
• Linux performance analysis and optimisation experience
• Understanding of:
  • Memory management
  • Shared memory
  • Memory-mapped files
  • Caching mechanisms
• Experience with JNI, Java Unsafe, JNR-FFI or similar native integrations

Nice to Have

• Hardware-aware performance optimisation
• High-frequency or real-time systems
• Benchmarking and latency analysis

Why This Role?

You'll be joining a highly technical engineering environment where performance is a core feature, not an afterthought.

Expect to work on:

• Ultra-low latency architectures
• Advanced JVM tuning
• High-performance networking
• Real-time processing systems

This is an opportunity to work alongside engineers who are passionate about squeezing every possible microsecond from a system and solving challenges few developers ever encounter.