As a Principal React Engineer you will be the technical leader driving the architecture and delivery of enterprise-scale web applications. This role goes beyond coding, you’ll define front-end strategy, set engineering standards, and influence product direction. You’ll design highly performant, resilient, and accessible user interfaces while mentoring teams and fostering a culture of technical excellence. Your expertise will shape reusable component libraries, modern development practices, and scalable solutions that power critical applications.

Reporting & Scope

Reporting to a Senior Engineering Manager, you’ll collaborate closely with multi-functional teams of product managers, UX designers, and backend engineers, to ensure seamless integration and an excellent user experience. This is an opportunity to lead innovation, solve sophisticated challenges, and make architectural decisions that impact thousands of users.

What You’ll Do

What You’ll Need to Succeed

Core Skills & Technologies

Preferred Experience

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 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, .

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.