Principal Applied Data Scientist

London Stock Exchange; Greater London; On-site; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Competitive compensation

Comprehensive benefits

Career growth investment

Job summary

London Stock Exchange is seeking a Principal Data Scientist to design, build, and deploy scalable AI solutions for production use in financial markets. You will lead hands-on technical work, applying NLP/LLMs, and collaborate with cross-functional teams to deliver robust models at scale.

The role requires deep NLP/LLM expertise, Python engineering skills, and experience shipping models in production with cloud deployment practices (Azure/AWS).

Qualifications

• Hands-on experience shipping models to production and supporting them post-deployment.
• Strong Python programming skills and object-oriented design.
• Solid understanding of probability and statistical modeling.
• Experience applying NLP and LLMs to real-world problems.

Responsibilities

• Lead end-to-end development of AI solutions: design, build, test, and deploy models.
• Write production-grade Python code following software engineering best practices.
• Collaborate with engineering and business partners to define requirements and roadmaps.
• Evaluate third-party AI solutions for performance, scalability, and production integration.
• Own delivery timelines and ensure solutions meet business needs and production standards.

Skills

Python programming

NLP & LLMs

ML libraries (PyTorch, TensorFlow, Sci

Education

Bachelor's degree (Engineering, CS, Data Science, Stats, Maths, Physics)

Tools

TypeScript

Cloud platforms (Azure/AWS)

Job description

• ROLE SUMMARY: 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’ll work closely with collaborative teams to co-develop innovative products for financial markets and professionals
• We’re looking for someone who combines deep technical expertise in NLP and LLMs, strong Python engineering skills, and real-world experience shipping and supporting models in production
• You should be comfortable owning delivery timelines and ensuring that solutions meet business needs and production-grade standards
• WHAT YOU’LL BE DOING: 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 that delivers 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
• 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
• High-impact projects: Work on innovative AI products that solve complex, high-value challenges using rich datasets
• Competitive benefits: Strong compensation, comprehensive benefits, and investment in your career growth
• Industry leadership: Be a founding member of a team delivering novel products that democratize modeling and analytics
• Collaborative environment: Join a team of experienced engineers in a culture of continuous learning and development

Strong Python programming skills, including object-oriented design and proficiency with key ML libraries (e.g., PyTorch, TensorFlow, Scikit-Learn)Solid understanding of probability and statistical modeling to support robust model development and interpretationProven ability to set and uphold coding and model evaluation standards for production environmentsExcellent communication skills to articulate technical decisions and trade-offs to both technical and non-technical audiencesExtensive 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-deploymentExperience with cloud platforms (especially Azure and/or AWS) and modern deployment practices for scalable AI deliveryEDUCATION Bachelor’s degree in Engineering, Computer Science, Data Science, Statistics, Mathematics, Physics or a related field, or equivalent practical experienceExperience with TypeScript, particularly for building or contributing to production services and APIs alongside ML systemsFamiliarity with DevOps practices including CI/CD, version control, automated testing, and monitoring to support reliable model deployment and maintenance