Data Scientist - Geo Holdout (12 Month FTC)

Location: London, United Kingdom. Hybrid work with teams in the office around four days a week. This is a UK-based role and requires the right to work in the UK.

Company

Media operating unit delivering AI-driven media, data, partnerships, and marketing technology for global clients, including Prime Video through the OpenDoor partnership.

What you will do

• Own the end-to-end technical implementation of a geo holdout programme covering up to 55 experiments across seven European markets.
• Build and maintain NUTS3-to-platform geo lookup tables using ONS and Eurostat boundary data for Meta, DV360, X, Sprinklr, and other media platforms.
• Develop campaign-to-experiment calendar scripts, API integrations, and bulk upload templates to apply and verify geo exclusions.
• Produce weekly NUTS3- and postcode-level verification reports, tracking impression leakage against defined accuracy thresholds.
• Oversee agentic QA outputs, resolve leakage and anomaly issues within programme SLAs, and extend automation as platforms and markets evolve.
• Collaborate with Measurement and Activation teams, document programme infrastructure, and support Poland and Turkey market onboarding.

Requirements

• Experience in data science, data engineering, or a closely related technical field.
• Hands-on experience with geospatial data, NUTS boundaries, postcode-level datasets, and tools such as PostGIS or QGIS.
• Strong proficiency in Python and/or R, SQL, and Git for data processing, scripting, automation, and version control.
• Experience with media platform APIs, including Meta Marketing API, Google DV360 API, or equivalent.
• Knowledge of incrementality measurement, geo holdout design, matched market testing, hypothesis testing, confidence intervals, and leakage effects.
• Experience operating automated QA or monitoring solutions, working with cloud technologies, and communicating technical results to non-technical stakeholders.

Nice to have

• Experience in a media agency or ad tech environment.
• Familiarity with NUTS3 boundary data across European markets, including Poland and Turkey.
• Experience with agentic AI solutions for automated monitoring or QA.
• Proficiency in one or more European languages.

Culture & Benefits

• Hybrid working model with frequent in-office collaboration and events.
• Medical, vision, dental, and group retirement plans.
• Significant paid time off, partner discounts, and mental health awareness days.
• Employee resource groups, professional development opportunities, and access to global company networks.