Principal Engineer (AWS & Java)

About Us:

LSEG (London Stock Exchange Group) is more than a diversified global financial markets infrastructure and data business. We are dedicated, open-access partners with a dedication to excellence in delivering the services our customers expect from us. With extensive experience, deep knowledge and worldwide presence across financial markets, we enable businesses and economies around the world to fund innovation, manage risk and create jobs. It’s how we’ve contributed to supporting the financial stability and growth of communities and economies globally for more than 300 years. Through a comprehensive suite of trusted financial market infrastructure services - and our open-access model - we provide the flexibility, stability and trust that enable our customers to pursue their ambitions with confidence and clarity.

LSEG is headquartered in the United Kingdom, with significant operations in 70 countries across EMEA, North America, Latin America and Asia Pacific. We employ 25,000 people globally, more than half located in Asia Pacific. LSEG’s ticker symbol is LSEG.

Our People:

People are at the heart of what we do and drive the success of our business. Our culture of connecting, creating opportunity and delivering excellence shape how we think, how we do things and how we help our people fulfil their potential. We embrace diversity and actively seek to attract individuals with unique backgrounds and perspectives. We break down barriers and encourage teamwork, enabling innovation and rapid development of solutions that make a difference. Our workplace generates an enriching and rewarding experience for our people and customers alike. Our vision is to build an inclusive culture in which everyone feels encouraged to fulfil their potential.

We know that real personal growth cannot be achieved by simply climbing a career ladder - which is why we encourage and enable a wealth of avenues and interesting opportunities for everyone to broaden and deepen their skills and expertise. As a global organisation spanning 70 countries and one rooted in a culture of growth, opportunity, diversity and innovation, LSEG is a place where everyone can grow, develop and fulfil your potential with meaningful careers.

Role Description

We are seeking a Principal Engineer to act as the most senior hands-on technical expert for our leading Risk Screening platform. This role partners closely with architecture, service, product, and engineering teams to ensure that agreed designs are implemented to the highest technical and operational standards.

A core focus of the role is ownership of the system’s non-functional characteristics, including end-to-end latency, cloud scalability, resilience, and the effective handling of large and growing data sets.

The Principal Engineer ensures these qualities are deliberately designed for, correctly implemented, and continuously validated in production.

Rather than owning architecture in isolation, the Principal Engineer is the expert implementor and problem solver: translating architectural intent into robust, performant, and secure production systems. You will use your knowledge of AWS Services and Java development to tackle the hardest technical challenges, proactively identify operational risks, and provide deep technical guidance that sets the highest standard across all engineering teams working on the product.

This is the most senior individual contributor role with broad influence, focused on technical excellence, delivery confidence, and long-term sustainability.

Technical Leadership & Implementation Excellence

• Act as the senior-most technical authority for implementation within the Risk Screening platform, ensuring designs are realised accurately and pragmatically.
• Work in close partnership with enterprise and solution architects to validate designs, challenge assumptions, and guide effective development approaches by the engineering teams.
• Lead the implementation of the most complex and business-critical changes, setting the standard for quality, performance, and maintainability.
• Provide hands-on expertise in Java-based systems, including concurrency, performance tuning, memory management, and API design.

Non-Functional Ownership & System Performance

• Take a leading role in defining, implementing, and validating non-functional requirements, including system latency, throughput, scalability, and reliability.
• Drive solutions for cloud scaling and capacity management, ensuring the platform performs predictably under variable and peak loads.
• Provide deep expertise in working with large databases and data stores, including performance optimisation, data access patterns, and operational scaling.

Problem Solving & Technical Decision Support

• Solve the most complex and ambiguous technical problems, particularly those spanning multiple components or teams.
• Act as a point of escalation for deep technical issues that require system-level understanding and experience.
• Support engineering teams in making sound technical decisions, helping them understand trade-offs and long-term consequences.

Cloud & Platform Expertise (AWS)

• Serve as a deep AWS expert, guiding teams on best-practice use of AWS services with a strong focus on elastic cloud scaling and performance under load.
• Ensure implementations support horizontal and vertical scaling, efficient resource utilisation, and predictable behaviour as demand grows.
• Guide and review approaches to autoscaling, and workload management, aligned with agreed architectures.
• Review cloud implementations to confirm they meet expectations for availability, scalability, cost-efficiency, and compliance.

Operational Excellence & Risk Management

• Proactively identify operational risks, scaling limits, and reliability concerns within existing and planned implementations.
• Drive improvements in resilience, monitoring, alerting, and incident prevention, informed by production behaviour.
• Partner with Site Reliability Engineers, platform, and operations teams to improve system operability and reduce customer impact.

Engineering Standards & Quality

• Champion engineering standards across coding, testing, deployment, and operational readiness.
• Conduct deep technical reviews of critical changes, focusing on non-functional requirements such as performance, security, and reliability.
• Help teams reduce technical debt through pragmatic, incremental improvements aligned to product priorities.

Coaching, Mentorship & Influence

• Act as a technical mentor and coach to senior engineers and technical leads across the organisation.
• Support engineers in developing stronger implementation skills and deeper system-level thinking.
• Influence engineering culture through example, constructive challenge, and a focus on practical excellence.

Required Skills & Experience

• Extensive experience as a Principal Engineer, or equivalent senior technical role on large-scale, production systems.
• Deep, hands-on expertise in Java (Java 11+ preferred), including JVM behaviour, concurrency, and performance optimisation.
• Strong, practical experience building and running systems on AWS, with a focus on real-world operational trade-offs.
• Proven ability to implement and operate distributed systems at scale, with particular emphasis on performance and scalability.
• Strong experience working with large databases or data platforms, including performance tuning and operational management.
• Strong understanding of production operations, including incident management, observability, and reliability engineering.
• Ability to influence and guide teams through technical credibility rather than formal authority.

Career Stage:

London Stock Exchange Group (LSEG) Information:

Join us and be part of a team that values innovation, quality, and continuous improvement. If you're ready to take your career to the next level and make a significant impact, we'd love to hear from you.

LSEG is a leading global financial markets infrastructure and data provider. Our purpose is driving financial stability, empowering economies and enabling customers to create sustainable growth.

Our purpose is the foundation on which our culture is built. Our values of Integrity, Partnership, Excellence and Change underpin our purpose and set the standard for everything we do, every day. They go to the heart of who we are and guide our decision making and everyday actions.

Working with us means that you will be part of a dynamic organisation of 25,000 people across 65 countries. However, we will value your individuality and enable you to bring your true self to work so you can help enrich our diverse workforce.

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.

You will be part of a collaborative and creative culture where we encourage new ideas. We are committed to sustainability across our global business and we are proud to partner with our customers to help them meet their sustainability objectives. Our charity, the LSEG Foundation provides charitable grants to community groups that help people access economic opportunities and build a secure future with financial independence. Colleagues can get involved through fundraising and volunteering.

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

Please take a moment to read this privacy notice carefully, as it describes what personal information London Stock Exchange Group (LSEG) (we) may hold about you, what it’s used for, and how it’s obtained, your rights and how to contact us as a data subject.

If you are submitting as a Recruitment Agency Partner, it is essential and your responsibility to ensure that candidates applying to LSEG are aware of this privacy notice.