Posted Thursday 22 January 2026 at 01:00 | Expires Sunday 8 February 2026 at 00:59
Below, you will find a complete breakdown of everything required of potential candidates, as well as how to apply Good luck.
At World of Books, we’re on a mission to become the Planet’s Bookstore — helping people read more while wasting less. As a certified B-Corp and a £200m+ global ecommerce business, data science sits at the heart of how we price millions of books sustainably and profitably.
We’re now looking for a Principal Data Scientist to play a critical technical leadership role in shaping how advanced modelling and experimentation are applied to pricing at scale.
The Role
This is a senior individual contributor role (no people management), focused on solving complex, high-impact pricing problems through experimentation, causal inference and applied machine learning.
You’ll work closely with our Data Science Manager, engineers and commercial leaders, acting as a technical authority and mentor while remaining hands‑on.
What You’ll Be Doing
- Leading advanced pricing optimisation, elasticity modelling and experimentation
- Designing and evaluating A/B tests, bandits and quasi-experiments
- Building and deploying production‑grade models with strong observability
- Setting practical standards for modelling, experimentation and DS workflows
- Mentoring senior and mid‑level data scientists through review and example
- Advising stakeholders on trade‑offs between rigour, speed and business value
- Identifying future high‑value data science use cases beyond pricing
What We’re Looking For
- Deep experience applying data science in commercial environments (pricing, ecommerce or marketplaces ideal)
- Expert Python and strong SQL
- Advanced knowledge of statistics, ML and causal inference
- Proven experience deploying and iterating on models in production
- Ability to influence through expertise and communicate clearly with senior stakeholders
- Pragmatic, outcome‑focused mindset with comfort in ambiguity
Why Join World of Books?
- Work on meaningful, planet‑positive problems at global scale
- A true Principal IC role with influence but no line management
- Partner closely with an experienced DS Manager who owns strategy and prioritisation
- Help shape how data science is practised in a growing, evolving organisation
- Be part of a mission‑driven, collaborative and inclusive culture
Interested? xwzovoh
If you’re a senior data scientist who thrives on complex problems, hands‑on technical leadership and real‑world impact — we’d love to hear from you.
World of Books is proud to be an equal opportunities employer and is committed to building a diverse and inclusive team.
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