Lead Software Engineer(Python/AWS/SQL)

Job Description Summary

Roles at Lead IC level solve complex problems and guide others through code, design, and architecture. Scope includes
owning technical direction and architecture in a defined area, mentoring peers, and raising quality through reuse and hands-on
support. The impact is consistent, high-quality solutions that reduce duplication and accelerate team delivery.​

## ROLE SUMMARY

Are you a software developer who loves building software that actually gets used?

Join us at FTSE Russell! We're building a team of engineers who care about software craftsmanship, clean code, and shipping things that matter. As a Software Engineer, you'll build the services, libraries, and applications that power the indices trusted by financial institutions worldwide.

We work primarily in Python, so that's our preference — but we care far more about whether you can genuinely build software than about which language you built it in. If your track record is in Java, C#, C, C++, Scala, Go, or Rust and you're keen to work in Python, we want to hear from you. Strong engineers pick up a new language quickly; strong engineering judgement takes years.

This is a hands-on software development role. You'll spend your days designing, coding, testing, and shipping — in a modern AWS environment, alongside engineers who review each other's code, pair when it helps, and take real ownership of what they build. The systems you work on handle serious volumes of financial data, so there's a rich data dimension to the problems — but the craft we're hiring for is software engineering.

If you've built real software and want to keep building, we'd love to meet you.

## WHAT YOU'LL BE DOING

We're building the next-generation index data platform at FTSE Russell — and we want you to help build it:

Looking for 10+yrs of experience in writing production code, primarily in Python — services, APIs, libraries, and command-line tools that are modular, well-tested, and built to be maintained by others
- Designing and building software components end to end, from breaking down a problem through to deployment and support in production
- Applying modern software engineering practices every day: version control, trunk-based development, CI/CD, code review, refactoring, and automated testing (unit, integration, contract)
- Taking ownership of features and systems — you debug your own problems, fix them properly, and take responsibility for the quality of what you deliver
- Designing data models and integrations across relational databases (Aurora PostgreSQL) and object storage, thinking carefully about schema design, evolution, and backwards compatibility
- Building software that processes data at scale on AWS — Lambda, S3, containerised services, and where appropriate the AWS data stack (Glue, EMR Serverless)
- Building observability in from the start — structured logging, metrics, tracing, and meaningful alerting, so that we know how our software behaves in production
- Contributing to design and architecture discussions, and to our shared engineering standards
- Working directly with product and business teams to turn requirements into working software
- Learning the financial indices domain and sharing what you learn with the team

## WHAT YOU'LL BRING

Essential — this is the bar:

- You have built and shipped real software. Not scripts and notebooks — applications, services, or libraries that other people depended on, that you maintained and evolved over time
- Python is our preference, but not a hard gate. Either you already write strong production Python, or you have that depth in another serious general-purpose language — Java, C#, C, C++, Scala, Go, or Rust — and are genuinely motivated to work in Python here. We'll give you the time and support to get fluent
- You write clean, maintainable, testable, extensible code. In Python that means type hints, linters and formatters (ruff, mypy, black), and a genuine testing habit with pytest; we'd expect the equivalent discipline in whatever language you've come from
- Strong software engineering fundamentals — modular design, sensible abstractions, dependency management, packaging, error handling, and knowing when *not* to add a layer
- You are hands-on and want to stay hands-on. You enjoy being in the code
- Practical experience with Git-based workflows, code review, and CI/CD
- Strong experience with relational databases (e.g. Aurora PostgreSQL) — schema design, query writing, and understanding what happens under the hood
- Working knowledge of a cloud platform, ideally AWS (S3, Lambda, containers, IAM basics)
- You're comfortable with data-shaped problems — batch processing, ETL, schema evolution — or you're keen to learn them
- You enjoy the business context and working closely with stakeholders rather than at arm's length
- You work well in Agile teams and value collaboration over solo heroics

## NICE TO HAVES

Great if you bring these, but we'll happily teach you:

- Apache Spark / PySpark or other large-scale distributed processing
- Big data experience — working with datasets and workloads that don't fit on one machine
- Additional languages used in data-intensive software — Scala, Java, C++, Go, or Rust — particularly where you've used them for performance-sensitive or high-throughput work
- Apache Iceberg, Delta Lake, or similar open table formats, and lakehouse architecture
- Databricks, Snowflake, or comparable data platforms
- CI/CD tooling such as GitLab CI, Jenkins, or GitHub Actions
- Infrastructure as code (Terraform, CDK)
- Data quality frameworks like Great Expectations or Deequ
- Curiosity about financial markets, index data, or investment analytics
- Experience in finance domain (investment banking, asset/portfolio management) or in any product company

---

Join us and be part of a team that values innovation, quality, and continuous improvement. If you're ready to build software that matters, we'd love to hear from you.

Career Stage:

Manager

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.