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.

Key responsibilities include leading the end-to-end development of AI solutions: designing, building, testing, and deploying models that are robust, scalable, and used by real users; applying NLP and LLM techniques to solve real-world problems with optimized performance and reliability; continuously improving model quality through tuning, evaluation, and feedback from production usage; evaluating third-party AI solutions for performance, scalability, and integration; writing and maintaining production-grade Python code adhering to best practices; and collaborating with engineering and business partners to define requirements, shape roadmaps, and ensure successful delivery of AI products.

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. We foster a collaborative and creative culture encouraging new ideas and are proud to be an equal opportunities employer.

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.
- Familiarity with DevOps practices including CI/CD, version control, automated testing, and monitoring to support reliable model deployment and maintenance is desirable.
- Experience with TypeScript, particularly for building or contributing to production services and APIs alongside ML systems, is a plus.
- Collaborative mindset with the ability to work effectively across engineering and business teams.

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