Senior Software Engineer

The Senior Fullstack Engineer applies strong software engineering principles and deep knowledge of the software development lifecycle to design, build, and guide the delivery of scalable, high-quality web applications. This role focuses on end-to-end development using React on the frontend and Node.js on the backend, while contributing to architectural decisions, mentoring engineers, and aligning technology solutions with business goals.

Role Responsibilities & Key Accountabilities

• Design, develop, and maintain complex full-stack applications using React, Node.js, and NestJS, ensuring performance, scalability, and maintainability.

• Act as a subject-matter expert in full-stack development, advising on architecture, design patterns, and implementation approaches.

• Produce clean, efficient, well-tested code and conduct thorough code reviews to uphold engineering standards and best practices.

• Lead and contribute to technical design discussions, adapting existing patterns or introducing new ones to deliver robust and reusable solutions.

• Collaborate with product managers, designers, and other engineers to plan and implement user journeys that meet business and customer objectives.

• Support the breakdown of Epics into technical solutions and actionable implementation tasks.

• Understand and apply the broader technology strategy, ensuring alignment with platform standards and adjacent teams.

• Take ownership of assigned deliverables, completing work with minimal supervision while providing guidance to less experienced engineers.

• Build strong working relationships with senior stakeholders and cross-functional teams, clearly communicating complex technical concepts to both technical and non-technical audiences.

• Promote an inclusive, open, and collaborative engineering culture.

• Continuously develop expertise in modern frontend and backend technologies, frameworks, and tooling through hands-on learning, certifications, and innovation initiatives.

• Develop an understanding of the organization’s commercial objectives and how technology solutions support them.

Qualifications & Experience

• Degree in Computer Science, Software Engineering, or equivalent practical experience.

• Strong professional experience with JavaScript/TypeScript, including:

  • React (modern hooks, state management, component design)

  • Node.js (NestJS) for building APIs and backend services

• Solid experience across the full software development lifecycle in an agile delivery environment.

• Experience working with multiple technologies and frameworks, with a strong understanding of when to apply specific design patterns and how to avoid anti-patterns.

• Familiarity with API design (REST and/or GraphQL), authentication/authorization, and integration with frontend applications.

• Working knowledge of testing strategies (unit, integration, end-to-end) and quality assurance practices.

• Some experience collaborating with stakeholders, including product, design, and delivery teams.

• Exposure to cloud-based environments, CI/CD pipelines, and modern DevOps practices is a plus.

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.

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