Lead C++ / Java Developer in London

The Senior Software Engineer is a hands-on individual contributor responsible for designing, building, and operating mission-critical FX market infrastructure and matching platforms using C++ and Java. The role focuses on low-latency, high-throughput distributed systems with strict availability, resiliency, and data integrity requirements. This role owns technical outcomes for complex components and services, influences architecture and platform evolution, and provides deep expertise across development, testing, and production support. While not a line-management role, it carries strong expectations for technical leadership, mentoring, and collaboration across engineering, architecture, and product teams.

Key Responsibilities

• Design, develop, and maintain C++ and Java services supporting FX matching and trading workflows.
• Own technical delivery for key platform components, ensuring alignment with LSEG architectural principles, performance standards, and operational controls.
• Build and evolve low-latency, high-availability systems handling high message volumes and time-critical processing.
• Ensure systems meet non-functional requirements, including latency, throughput, resiliency, fault tolerance, security, and observability.
• Contribute to system and solution architecture, participating in design reviews and providing pragmatic input on scalability and operability.
• Work closely with Product, QA, SRE, and Architecture teams to translate business requirements into robust technical solutions.
• Diagnose and resolve complex issues across production, QA, and client environments, including root-cause analysis of cross-system failures.
• Improve code quality and maintainability through clean design, automated testing, performance tuning, and controlled refactoring.
• Integrate and manage dependencies on messaging platforms, data distribution systems, and upstream/downstream market infrastructure.
• Evaluate and adopt suitable open-source and third-party technologies, ensuring they meet regulatory, security, and performance requirements.
• Provide technical mentoring through code reviews and design discussions across teams.
• Ensure adherence to SDLC standards, engineering best practices, and operational readiness requirements.
• Contribute recommendations that influence platform standards, engineering patterns, and architectural direction across FX technology.

Minimum Requirements

• Bachelor’s degree in Computer Science, Engineering, or equivalent practical experience.
• Strong hands-on experience in both C++ and Java, delivering production-grade systems.
• 10+ years of software engineering experience as a senior individual contributor.
• Proven delivery experience with low-latency, high-throughput, distributed systems, ideally in FX, trading, or matching platforms.
• Strong understanding of system integration, messaging, event-driven architectures, and data consistency.
• Experience working across the full SDLC, including design, development, automated testing, deployment, and production support.
• Familiarity with Linux, CI/CD pipelines, build systems, performance testing, and monitoring/alerting.
• Practical experience with cloud platforms, containerization, and open-source technologies.
• Excellent problem-solving skills and the ability to influence technical outcomes without formal authority.
• Up-to-date with modern engineering practices, tools, and industry trends.

Benefits

LSEG offers a range of tailored benefits and support, including healthcare, retirement planning, paid volunteering days and wellbeing initiatives.

Equal Opportunity Statement

We are proud to be an equal opportunities employer. This means that we do not discriminate on the basis of anyone’s race, religion, colour, national origin, gender, sexual orientation, gender identity, gender expression, age, marital status, veteran status, pregnancy or disability, or any other basis protected under applicable law. Conforming with applicable law, we can reasonably accommodate applicants’ and employees’ religious practices and beliefs, as well as mental health or physical disability needs.