Location
Paternoster Square, London

Hours
Full Time

Salary
Negotiable

About the Role
Are you a hands-on data scientist with deep expertise in NLP and LLMs, strong Python coding skills, and a track record of deploying models to production? Do you thrive in building real-world AI solutions that are used by actual customers? If so, we'd love to talk to you! As a Principal Data Scientist (individual contributor), you will play a hands-on role in designing, building, and deploying scalable AI solutions that go beyond prototypes and are actively used in production. You will work closely with collaborative teams to co-develop innovative products for financial markets and professionals. This role requires deep technical expertise in NLP and LLMs, strong Python engineering skills, and real-world experience shipping and supporting models in production. You will own delivery timelines and ensure solutions meet business needs and production-grade standards.

This is a hands-on technical leadership role in a high-impact environment focused on delivering production-ready AI systems. You will be part of the LSEG Workspace team — LSEG's flagship platform delivering personalised insights, news, and cutting-edge analytics to financial professionals worldwide. Your work will directly shape the AI capabilities embedded in a product that professionals rely on every day to make critical decisions.

You will lead the end-to-end development of AI solutions: design, build, test, and deploy models that are robust, scalable, and used by real users. Apply NLP and LLM techniques to solve real-world problems, ensuring models are optimized for performance and reliability. Continuously improve model quality through tuning, evaluation, and feedback from production usage. Evaluate third-party AI solutions with a critical eye on performance, scalability, and integration into production environments. Write and maintain production-grade Python code, adhering to best practices in software engineering and model development. Collaborate with engineering and business partners to define requirements, shape roadmaps, and ensure successful delivery of AI products.

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

Join us and be part of a team that values innovation, quality, and continuous improvement. LSEG is a leading global financial markets infrastructure and data provider, committed to driving financial stability, empowering economies, and enabling customers to create sustainable growth. Working with us means being part of a dynamic organisation of 25,000 people across 65 countries, where your individuality is valued and you can bring your true self to work. We foster a collaborative and creative culture encouraging new ideas and are committed to sustainability and community support through the LSEG Foundation.

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

Experience
- Extensive hands-on experience applying NLP and LLMs to real-world problems, with a consistent track record of shipping models to production and supporting them post-deployment.
- Strong Python programming skills, including object-oriented design and proficiency with key ML libraries such as PyTorch, TensorFlow, and Scikit-Learn.
- Solid understanding of probability and statistical modeling to support robust model development and interpretation.
- Experience with cloud platforms (especially Azure and/or AWS) and modern deployment practices for scalable AI delivery.
- Proven ability to set and uphold coding and model evaluation standards for production environments.
- Excellent communication skills to articulate technical decisions and trade-offs to both technical and non-technical audiences.

About you
- Comfortable owning delivery timelines and ensuring solutions meet business needs and production-grade standards.
- Collaborative mindset with ability to work closely with engineering and business partners.
- Passionate about building production-ready AI systems that have real-world impact.
- Familiarity with DevOps practices including CI/CD, version control, automated testing, and monitoring is desirable.
- Experience with TypeScript, particularly for building or contributing to production services and APIs alongside ML systems, is a plus.

Qualifications
Bachelor's degree in Engineering, Computer Science, Data Science, Statistics, Mathematics, Physics, or a related field, or equivalent practical experience.