Software Engineer - High-Performance Java / Low Latency

Randstad Technologies Recruitment; Greater London; Hybrid; GBP 120,000 - 194,000; Full time

Job summary

Randstad Technologies Recruitment in London is seeking a specialist High-Performance Java Engineer to expand agency liquidity on Principal Risk. You will join a team delivering low-latency trading platforms, working hybrid from London with three days in-office.

The role requires expert Java, JVM internals, and experience with memory profiling, GC tuning, and JNI/JNR-FFI. Collaboration with CRB and risk teams across EMEA and US is essential.

Qualifications

• Deep expertise in Java performance engineering and JVM internals.
• Experience with GC tuning, memory profiling, and low-latency systems.
• Familiarity with low-level Java APIs (Unsafe, JNI, JNR-FFI).

Responsibilities

• Design and build high-throughput, low-latency Java systems for trading platforms.
• Perform JVM tuning and memory optimization to achieve ultra-low latency.
• Collaborate with risk and engineering teams on cross-regional projects.
• Develop low-level Java solutions using JNI/JNR-FFI as needed.

Skills

Core Java & JVM

Low-Level APIs

Architecture & Concurrency

Networking & OS Internals

Tools

Aeron

Job description

Software Engineer - High-Performance Java / Low Latency

Role Type: Contract (Inside IR35)

Location: London, UK (Hybrid - 3 days per week in-office)

Overview

We are looking for a specialist High-Performance Java Engineer to join our team in London, focusing on the expansion of Agency Liquidity based on Principal Risk. In this role, you will work closely with CRB to drive key EMEA and US regional projects, developing low-latency, event-driven trading platforms.

Core Responsibilities

• Design, build, and optimize high-throughput, low-latency concurrent systems for agency liquidity expansion.
• Perform fine-grained JVM tuning, garbage collection (GC) optimization, and memory profiling to achieve ultra-low response times.
• Engineer low-level Java solutions utilizing JNI, Java Unsafe, or JNR-FFI for high-frequency processing.
• Collaborate across cross-functional engineering and risk teams to execute high-impact EMEA and US project deliverables.

Technical Requirements

• Core Java & JVM: Deep expertise in Java high-performance engineering, JVM internals, garbage collection strategies, and profiling.
• Low-Level & Hardware Optimization: Solid foundation in low-level Java APIs (Unsafe, JNI, JNR-FFI), CPU architecture, shared memory, and memory-mapped files.
• Architecture & Concurrency: Mastery of event-driven/reactive designs, multi-threading, concurrent programming patterns, and core Data Structures & Algorithms.
• Networking & OS Internals: Strong hands-on knowledge of networking protocols (TCP/UDP, low-latency socket programming) and Linux kernel/memory management.

Technical Nice-to-Have

• Hands-on experience with the Aeron messaging framework or similar ultra-low-latency messaging technologies.