Senior Software Engineer

Senior C++ Engineer

Are you a software engineer passionate about building high-performance, low-latency systems? Do you want to leverage your C++ expertise in an exciting, high-impact fraud prevention environment where your code processes billions of transactions worldwide?

About the Business LexisNexis is a data and analytics company with 10,500 colleagues serving customers in more than 150 countries. We're one of the largest information and analytics companies on the planet. We design solutions that help our customers increase productivity, improve decision-making and outcomes, and be more successful.

About our Team ThreatMetrix, a part of RELX, is a global leader in digital identity intelligence and fraud prevention. Our engineering teams build high-performance systems that process billions of transactions, helping organizations make trusted decisions in real time.

Our team builds and maintains high-throughput, low-latency systems that process massive volumes of transactions in real time. Engineers in this team collaborate closely with data scientists, platform engineers, and product managers to deliver systems that power trusted decisioning at global scale.

About the Role As a Senior C++ Engineer, you will play a pivotal role in designing and developing high-performance, low-latency backend systems at the core of our fraud prevention platform. You will leverage your expertise in modern C++, multi-threaded programming, and distributed systems to build and optimise services that process massive volumes of transactions in real time across multiple regions worldwide. Reporting to the Engineering Manager, this is a full-time role within a high-performing engineering team. This role will be based in Australia (Sydney preferred), with flexibility to work from home.

You will work with modern C++, NoSQL databases, message queues, and scripting layers, contributing to a platform deployed across multiple data centres — a mixture of on-premises clusters and cloud-based infrastructure — orchestrated via Kubernetes.

Responsibilities

• Design and develop high-performance C++ backend services and components
• Build and optimise multi-threaded, low-latency systems for real-time transaction processing
• Work with NoSQL databases and message queue technologies to handle large-scale data flows
• Contribute to scripting and configuration layers that drive system behaviour
• Collaborate with teams building microservices in Go and Python to deliver end-to-end solutions
• Troubleshoot, profile, and improve system performance, scalability, and reliability
• Contribute to system architecture, design decisions, and engineering best practices
• Review code and mentor junior engineers
• Ensure high-quality, maintainable, and testable code through static analysis, sanitizers, and thorough testing

Requirements

• Strong proficiency in modern C++ (C++17/20)
• Solid experience with multi-threaded and concurrent programming
• Experience with CMake or similar C++ build systems
• Strong Linux systems programming skills
• Solid understanding of distributed systems and microservices architecture
• Experience with NoSQL databases (e.g., Aerospike, Cassandra, or similar)
• Experience with message queue technologies (e.g., Kafka, ActiveMQ, or similar)
• Proven ability to profile, debug, and tune performance-critical systems
• Strong problem-solving and debugging skills
• Ability to work in a fast-paced, collaborative environment

Desirable

• Working experience with Python
• Experience with Lua scripting
• Experience with Go
• Familiarity with Boost libraries
• Familiarity with RPC frameworks (e.g., Thrift, gRPC)
• Experience with Kubernetes and Docker
• Prior experience in the fraud prevention or fintech domain

Work in a way that works for you We promote a healthy work/life balance across the organization, with various flexible and remote working options available to employees.

Working for you We know that your wellbeing and happiness are key to a long and successful career. These are some of the benefits we are delighted to offer:

• Discounted Health plan rate and Optical Assistance
• Life assurance and income protection
• Option to buy additional Annual Leave days
• Employee Assistance Program
• Flexible working arrangements
• Benefits for you and your family
• Access to learning and development resources

We are looking to fill this role as soon as possible – apply now to be considered. Thank you for your interest.