Principal Data Scientist, Experimentation

Location: London, United Kingdom; hybrid

Company

hirify.global is a Tripadvisor travel experiences business connecting a global audience with travel activities through content, technology, and a two-sided marketplace.

What you will do

• Set technical standards for experimentation across Product Data Science, including A/B testing, quasi-experimental methods, and Bayesian approaches.
• Build protocols, frameworks, tooling, and self-service capabilities that help teams experiment independently and reliably.
• Own measurement strategies for complex hirify.global questions where standard experimentation is insufficient.
• Develop and validate statistical methods, including simulation-based verification, variance reduction, proxy metrics, and approaches for low-traffic surfaces.
• Act as the final technical authority on measurement validity and advise when experimentation is not the appropriate method.
• Mentor senior data scientists and partner with Product, Engineering, and Data Platform teams to improve experimentation quality and velocity.

Requirements

• Extensive experience in data science or a related quantitative role supporting and influencing product organisations.
• Authoritative expertise in experimental design, variance reduction, causal inference, multi-arm bandits, and Bayesian methods.
• Expert proficiency in Python and SQL, with hands-on experience in statistical modelling and machine learning, including regression, classification, and clustering.
• Experience defining and operationalising product and feature-level metrics and standardising methods across multiple teams.
• Strong cross-functional communication and the ability to explain methods, measurement, and uncertainty to technical and non-technical audiences.
• Bachelor's degree in Statistics, Mathematics, Data Science, Engineering, Physics, Economics, or a related quantitative field.

Nice to have

• Experience with experimentation in two-sided marketplaces, travel technology, e-commerce, or other high-scale technology companies.
• Experience with proxy or surrogate metrics, Bayesian hierarchical approaches, and low-traffic or long-horizon measurement.
• Experience building experimentation platforms, measurement frameworks, self-service capabilities, or data products.
• Experience applying AI, large language models, agentic AI, or automation to analytical work.
• Familiarity with Statsig, Eppo, GrowthBook, or an in-house experimentation platform.

Culture & Benefits

• Hybrid working arrangement in London.
• Collaboration with Product, Engineering, Data Platform, and other central functions.
• Accessible and inclusive recruitment experience with reasonable accommodations available.