Senior Data Scientist

GT was founded in 2019 by a former Apple, Nest, and Google executive. GT's mission is to connect the world's best talent with product careers offered by high-growth companies in the UK, USA, Canada, Germany, and the Netherlands.

On behalf of Mercer, GT is seeking a Senior Data Scientist / AI Consultant to partner with multiple teams across the client's organization — transforming fragmented data into actionable insights, and delivering production-ready, LLM-powered solutions that drive Mercer's AI strategy.

**Contract Duration: 6 months (with possible extension until the end of 2026)

Mercer is a global consulting leader in advancing health, wealth, and career outcomes for organizations and individuals. Headquartered in New York City, Mercer operates in over 130 countries with more than 25,000 employees and 180+ office locations worldwide. As part of Marsh McLennan, Mercer provides data-driven insights and tailored solutions in areas such as HR transformation, compensation and benefits, workforce analytics, and employee experience. The company fosters a collaborative, inclusive, and purpose-driven culture that values innovation, integrity, and impact.

We are looking for a Senior Data Scientist / AI Consultant with proven experience in productionizing ML models and working with Large Language Models (LLMs).

In this role, you'll work on a variety of AI initiatives, collaborating with different teams to solve complex problems, shape data strategies, and deliver production-ready solutions. You'll have the opportunity to influence multiple parts of the business while working with autonomy and the support of experienced stakeholders, all aligned to Mercer's 2026 AI strategy.

If you thrive in environments where you can own problems end-to-end, balance multiple priorities, and combine technical excellence with strategic insight, this role is for you.

• End-to-End Model Deployment: Design, productionize, and validate machine learning and LLM-based solutions for real-world applications.

• AI Infrastructure Planning: Help shape the foundations for Mercer's AI capabilities, ensuring scalability and maintainability.

• Requirement Analysis & Prioritization: Gather, assess, and prioritize requirements from multiple stakeholders and projects.

• Data Structuring & Guidance: Identify fragmented data sources and define optimal structures for analysis and ML use.

• Strategic Data Insights: Provide actionable recommendations that connect technical solutions to business objectives.

• Cross-Project Collaboration: Engage with multiple teams to deliver AI solutions that address diverse business needs.

• Production-Ready Delivery: Own the full lifecycle of ML/LLM solutions, including deployment, API integration, monitoring, and iterative improvement.

• 5+ years in a data science or ML engineering role.

• Proven track record of deploying ML/LLM models into production (APIs, microservices, cloud endpoints, integration workflows).

• Strong Python skills for data analysis, ML pipelines, and LLM integration.

• Proficiency in SQL for working with large datasets.

• Experience with LLM frameworks (OpenAI, Hugging Face).

• Solid understanding of data modeling, exploratory analysis, and statistical testing.

• Ability to validate and monitor model performance post-deployment (data drift, model drift, LLM evaluation patterns).

• Strong critical thinking skills for navigating multi-stakeholder environments.

• Ability to manage multiple projects independently.

• Excellent communication skills for both technical and non-technical audiences.

• Experience in the HR, people management, or compensation domains.

• Knowledge of MLOps best practices for deployment, CI/CD, and model monitoring.

• Experience with data visualization tools (e.g., Tableau, Power BI).

• Background in product management or product strategy.

1. Interview with GT Recruiter

2. Technical Interview with Mercer

3. Final Interview