About WPP Media WPP is the trusted growth partner for the world’s leading brands. With exceptional talent, trusted data and intelligence, and world-class partnerships – all united by our pioneering agentic marketing platform, WPP Open – we help clients navigate change, capture opportunity, and deliver transformational growth.  WPP Media is WPP's AI-driven media operating unit, bringing together media, data, and partnerships to deliver creative personalisation at scale. Connected through WPP Open and powered by Open Intelligence, clients see exactly where, how, and why their media investment is working. For more information, visit [wppmedia.com](wppmedia.com). 2576 - Data Scientist Geo Holdout & Incrementality (12 Month FTC) - GCS Role Summary and Impact The purpose of this document is to help prospective team members better understand the role and responsibilities for the position of Data Scientist — Geo Holdout Programme at OpenDoor, WPP's bespoke global operating model for Amazon. ABOUT WPP & OPENDOOR At WPP, we're constantly reinventing the future of creativity on an ever-broader canvas, bringing together unrivalled talent, resources and skills to provide an integrated offer of communications, experience, commerce and technology. Over the last decade, we have developed a dedicated global client practice with the mission of accelerating WPP's impact for our largest clients by bringing them the best of WPP. Each team is custom-built around a client's specific needs and challenges, providing easy access to the right capabilities. And that's why we've built OpenDoor for Amazon. OpenDoor is a unique integration of the best of WPP and Amazon – building on their respective strengths and visions. Whether at WPP or at Amazon, every project is an OpenDoor on new possibilities. Anything and everything can be an opportunity for our people to drive impact – for them to innovate, learn, thrive, and occasionally fail too. The unique OpenDoor partnership model is built to deliver next-level Productivity, fueled by our industry-leading approach to People, Platforms, and Process. OpenDoor spans across all WPP agencies and disciplines such as media, business consultancy, communications and brand strategy, tech and commerce, public relations, and production. OpenDoor's values are built from Amazon's own 16 Leadership Principles, and WPP's core values of Open, Optimistic and Extraordinary. Together, when WPP's Creative Transformation meets Amazon's next-level customer centricity, our people come together to challenge and impact what's done today and build a better future. By joining OpenDoor, not only are you joining a cross-function team partnering with one of WPP's top five global clients, but you are also taking a step to challenge yourself and the world around you every day, working in the most unusual way on some of Earth's most ambitious opportunities in marketing, tech, media, business, and creativity. ABOUT THE ROLE We are searching for a talented and technically exceptional individual to join our OpenDoor team as a Data Scientist, dedicated to the delivery of Prime Video's expanded geo holdout programme across Europe. This is a full-time permanent position based in London. The role reports into the EU Measurement Lead. This is a rare opportunity to own the technical backbone of one of the most analytically rigorous media measurement programmes in market — designing and operating the infrastructure that enables up to 55 geo holdout experiments across seven European markets, including the UK, Germany, France, Spain, Italy, and optional extension into Poland and Turkey. The work sits at the intersection of geospatial data engineering, media platform API integration, and incrementality measurement, and will directly inform how Prime Video plans and invests in theatrical and streaming campaigns across APAC and Europe. RESPONSIBILITIES - Own the end-to-end technical implementation of the geo holdout programme, serving as the dedicated technical lead across all markets and experiment waves - Construct and maintain the NUTS3-to-platform geo lookup table, mapping regional boundary data from ONS and Eurostat sources to platform-specific geo targeting formats across Meta, DV360, X, Sprinklr, and all other in-scope media platforms - Build and operate the weekly campaign-to-experiment calendar matching script, ensuring geo exclusions are flagged, applied, and verified ahead of each experiment activation - Develop and maintain API scripting and bulk upload templates to apply and verify geo exclusions directly within each platform's native geo-targeting capabilities - Produce and validate weekly verification reporting at NUTS3 and postcode level, delivered to key Prime Video stakeholders every Friday, clearly documenting impression leakage rates against the programme's defined accuracy thresholds - Own human oversight of the agentic QA solution — reviewing automated flags for impression leakage, exclusion drift, and reporting anomalies, and ensuring all issues are resolved within programme SLAs - Maintain and extend the automation layer as platform APIs evolve, new markets are onboarded, and programme complexity grows - Support the onboarding of Poland and Turkey as extension markets, including sourcing and validating boundary data, confirming platform geo targeting capability, and configuring the QA solution to reflect the elevated 6% leakage tolerance applicable during the first three experiments in each market - Contribute to quarterly performance reviews and the annual scope review milestone, providing technical input on programme performance, leakage trends, and automation maturity - Document all geo mapping logic, API scripts, QA frameworks, and processes to the standard required for long-term programme infrastructure — ensuring continuity, auditability, and reusability across future market expansions - Collaborate with the Measurement and Activation teams to ensure the technical layer integrates seamlessly with campaign planning and go-live workflows - Stay current with developments in geospatial data, platform API capabilities, and agentic automation tooling, proactively identifying opportunities to improve programme efficiency and accuracy Skills and Experience - Experience in data science, data engineering, or a closely related technical field - Demonstrable experience working with geospatial data, including NUTS boundary frameworks, postcode-level geographic datasets, and tools such as PostGIS, QGIS, or equivalent - Strong proficiency in Python and/or R for data processing, scripting, and automation; SQL for data querying and transformation; and version control via Git - Hands-on experience working with media platform APIs — ideally Meta Marketing API, Google DV360 API, or equivalent — including building scripts for programmatic data retrieval and campaign modification - Solid understanding of incrementality measurement methodologies, including geo holdout design, matched market testing, and the statistical principles underpinning experiment validity - Strong understanding of statistics including hypothesis testing, significance thresholds, confidence intervals, and the implications of leakage and contamination on experiment readability - Experience building and operating automated QA or monitoring solutions, with the ability to configure alerting logic and interpret anomaly outputs - Experience with cloud technologies including AWS, GCP, or Azure; familiarity with serverless architecture and data pipeline tooling is an advantage - Strong communication skills — able to translate complex technical outputs into clear, accessible reporting for non-technical stakeholders at Prime Video and within the wider OpenDoor team - High degree of ownership and accountability; comfortable working to defined SLAs in a programme environment where experiment integrity directly affects client investment decisions - Experience working within a cross-functional team using project management tools such as Jira or equivalent BONUS POINTS - Experience working within a media agency or ad tech environment - Familiarity with NUTS3 boundary data across multiple European markets, including Poland and Turkey - Experience configuring or working alongside agentic AI solutions for automated monitoring or QA - Proficiency in one or more European languages Life at WPP Media & Benefits Our passion for shaping the next era of media is powered by our commitment to Be Extraordinary, investing in our employees to inspire transformational creativity. We also Lead Optimistically, firmly believing in and Championing Growth and Development for every individual. This commitment allows WPP Media employees to leverage the extensive global WPP Media & WPP networks to pursue their passions, build vital professional connections, and learn at the cutting edge of marketing and advertising.  We Create an Open environment built on trust and respect, where everyone feels they belong and has opportunities to progress. This inclusive culture is fostered through a variety of employee resource groups and frequent in-office events showcasing team wins, sharing thought leadership, and celebrating holidays and milestone events. Our comprehensive benefits package reflects this commitment, including competitive medical, group retirement plans, vision, and dental insurance, significant paid time off, preferential partner discounts, and employee mental health awareness days.  WPP Media is an equal opportunity employer and considers applicants for all positions without discrimination or regard to characteristics. We believe the best work happens when we're together, fostering creativity, collaboration, and connection in this open and supportive environment. That's why we’ve adopted a hybrid approach, with teams in the office around four days a week. If you require accommodations or flexibility, please discuss this with the hiring team during the interview process.  Please note that while our philosophy is the same across WPP, benefits may vary by office/country. Please note this is a UK based role and requires individuals to have the right to work in this location Please read our Privacy Notice ([https://www.wppmedia.com/pages/privacy-policy)](https://www.wppmedia.com/pages/privacy-policy) for more information on how we process the information you provide. While we appreciate all applications received, only those candidates selected for an interview will be contacted.  #LI-Promoted Please read our [Privacy Notice](https://www.wppmedia.com/pages/privacy-policy#:~:text=WPP%20Media%20Privacy%20Notice%20for%20Recruitment) for more information on how we process the information you provide.