Principal Data Scientist, Experimentation

Tripadvisor; Greater London; Hybrid; GBP 120,000 - 180,000; Full time

Job summary

Tripadvisor seeks a Principal Data Scientist in London to lead experimentation strategy and measurement standards across products. You will set technical direction, mentor teams, and partner with Product, Engineering and Data Platform to raise speed and rigor in experiments.

You will own complex measurement questions, develop robust statistical methods, and ensure results align with platform health and growth goals for the organisation.

Qualifications

• Authoritative command of experimentation in all its forms, from experimental design and variance reduction to causal inference, bandits and Bayesian methods.
• Expert level proficiency in Python and SQL; deep experience with statistical modelling, quasi-experimentation, multi-arm bandits and ML techniques.
• Define, implement and operationalise crucial product and feature-level metrics from scratch.
• Partnership and enablement to raise both speed and quality of experimentation across teams.
• Ability to assess how product decisions affect platform health and growth over time.

Responsibilities

• Set the technical standard for experimentation across Product Data Science, from conventional A/B testing to quasi-experimental and Bayesian methods, and make it practical through protocols, frameworks and tooling.
• Partner with Product, Engineering and Data Platform teams to improve experimentation velocity without sacrificing rigour.
• Critically assess how experimentation and the decisions that follow it affect platform health and growth, and make that relationship visible to leadership.
• Own the measurement approach for Viator's most complex questions, where standard experimentation is insufficient and the method has to be designed rather than selected.
• Develop and validate the statistical methods the organisation relies on, including simulation-based verification that they behave correctly before teams depend on them.
• Act as the final technical authority on measurement validity, adjudicating disputed results and determining what the evidence does and does not support.
• Standardise recurring analytical and experimentation processes across the function, using automation and AI capabilities where they materially improve consistency, throughput or quality.
• Design and land methodological improvements with organisation-wide impact, such as variance reduction for difficult metrics and designs for low-traffic surfaces.
• Grow the technical depth of the wider team by reviewing designs, mentoring senior data scientists, and improving how people reason about measurement.
• Advise on where experimentation is the wrong tool and define what should be done instead.

Skills

Python

SQL

Statistics

Experimentation

Causal inference

Multi-armed bandits

Machine learning

Communication

Education

Bachelor's degree in Statistics or related quantitative field

Tools

Statsig

Eppo

GrowthBook

Job description

London

About Tripadvisor

The Tripadvisor Group connects people to experiences worth sharing, and aims to be the world's most trusted source for travel and experiences. We leverage our brands, technology, and capabilities to connect our global audience with partners through rich content, travel guidance, and two-sided marketplaces for experiences, accommodations, restaurants, and other travel categories. The subsidiaries of Tripadvisor, Inc. (Nasdaq: TRIP), include a portfolio of travel brands and businesses, including Tripadvisor, Viator, and TheFork.

At Tripadvisor experiences, the only thing we love more than travel is data. We slice it, we dice it, and we use it to empower our decision making.

What You will do:

As a Principal Data Scientist you will be a leading individual contributor responsible for how experimentation works across the organisation.

You will lead through technical depth, setting the standards others work to and raising the quality of measurement and decision-making across the function.

You will build the capability that lets teams experiment well without central support: the standards, tooling and protocols that make good practice the default, and a strategy for how it develops over time.

Both the speed and the reliability of decision-making should improve as a result. You will also take on the measurement questions we cannot currently answer well, where traffic is thin or the outcomes that matter take months to appear.

You will:

• Set the technical standard for experimentation across Product Data Science, from conventional A/B testing to quasi-experimental and Bayesian methods, and make it practical through protocols, frameworks and tooling.
• Partner with Product, Engineering and Data Platform teams to improve experimentation velocity without sacrificing rigour.
• Critically assess how experimentation and the decisions that follow it affect platform health and growth, and make that relationship visible to leadership.
• Own the measurement approach for Viator's most complex questions, where standard experimentation is insufficient and the method has to be designed rather than selected.
• Develop and validate the statistical methods the organisation relies on, including simulation-based verification that they behave correctly before teams depend on them.
• Act as the final technical authority on measurement validity, adjudicating disputed results and determining what the evidence does and does not support.
• Standardise recurring analytical and experimentation processes across the function, using automation and AI capabilities where they materially improve consistency, throughput or quality.
• Design and land methodological improvements with organisation-wide impact, such as variance reduction for difficult metrics, approaches for low-traffic surfaces, proxy and surrogate metrics for long-horizon outcomes, and designs that hold up where users compete for shared supply.
• Grow the technical depth of the wider team by reviewing designs, mentoring senior data scientists, and improving how people reason about measurement.
• Advise on where experimentation is the wrong tool and define what should be done instead.

Skills & Experience:

• Experience: Extensive experience in data science or a similar quantitative role, with a proven track record of supporting and influencing a product organisation.
• Statistical & Experimentation Expertise: Authoritative command of experimentation in all its forms, from experimental design and variance reduction to causal inference, bandits and Bayesian methods. You should be able to develop and validate methodology, not only apply it.
• Technical & Modelling Expertise: Expert level proficiency in Python and SQL. Deep, hands-on experience with statistical modelling, (quasi) experimentation, multi-arm bandits, and a wide range of machine learning techniques such as regression, classification and clustering.
• Product Acumen: Demonstrated ability to define, implement and operationalise crucial product and feature-level metrics from scratch.
• Partnership & Enablement: Demonstrated ability to improve how other teams work by providing guidance, tooling and protocols, increasing both the speed and the quality of their experimentation rather than absorbing the work yourself.
• Decision Impact & Platform Health: Ability to critically assess how product decisions affect platform health and growth over time, and to bring that perspective into how experiments are designed and interpreted.
• Standardising at Scale: Experience standardising processes, frameworks or methods across multiple teams, including the use of AI and automation to make good practice the default.
• Cross-Functional Partnership: Proven ability to build strong relationships and drive outcomes across Product, Engineering, Data Platform and other central functions, often without direct authority.
• Critical Thinking: Leader in critical thinking, with a demonstrated habit of establishing whether a result is trustworthy before establishing what it means.
• Communication: Exceptional ability to explain measurement, method and uncertainty clearly to technical and non-technical audiences at every level.
• Education: Bachelor's degree in Statistics, Mathematics, Data Science, Engineering, Physics, Economics, or a related quantitative field.

You could be an especially great fit if you have:

• Experience with experimentation in a two-sided marketplace, where interference between users and finite shared supply complicate measurement.
• Experience building and validating proxy or surrogate metrics for long-horizon outcomes, and a clear view of how far they can be trusted.
• Experience with Bayesian and hierarchical approaches, particularly for low-traffic surfaces or pooling evidence across many small markets.
• Experience building or materially improving experimentation platforms, measurement frameworks, self-service capabilities or data products.
• Experience in a high-scale technology company, marketplace, e-commerce business or travel technology organisation, and familiarity with the seasonality and long purchase cycles that come with them.
• Breadth in statistical modelling and machine learning, such as regression, classification, clustering and bandits, alongside your experimentation depth.
• Experience applying AI, Large Language Models, agentic AI or automation to improve analytical productivity and decision-making effectiveness.
• A reputation for raising the standard of thinking and decision-making in every team you join.
• Experience with SaaS experimentation tools such as Statsig, Eppo or GrowthBook, or with an in-house platform.

We strive to create an accessible and inclusive experience for all candidates. If you need a reasonable accommodation during the application or the recruiting process, please make sure to reach out to your individual recruiter or our team at [e-mail].

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