Data Scientist

OVERVIEW:NEXT is the newly launched innovation hub inside Fifty5Blue, the global leader in media measurement and analytics operating in more than 80 countries. NEXT is a new, ring-fenced innovation unit being built from the ground up, with a clear mandate to launch the next generation of AI-native audience-intelligence products — modernizing our cross-media engine, expanding our audience measurement solutions, and investing in AI capabilities.Why join this incredible program? NEXT is being built from the ground up - you will shape both the product and the operating model. Flexible work model: London (one pod is being built in our London office) or fully remote with regular travel for in person collaboration. Hybrid by default; we trust our teams to find the right balanceTHE ROLENEXT is seeking an experienced Data Scientist to lead applied research and methodology for our audience-measurement initiatives. The work spans cross-media calibration, behavioural-panel signal extraction, synthetic panellists, and AI-on-panel use cases. You'll be working with real panel data, real customer pilots, and real methodological standards — radical experimentation under measurement-science rigour.KEY RESPONSIBILITIESApplied research & modellingLead applied ML/statistics work for scoped proof of concepts across audience measurementDesign and prototype new measurement methodologies; validate against panel and external benchmarks.Bring techniques from adjacent fields (synthetic data, agentic systems, foundation models) into measurement contextsProductionisation & validationMove prototypes from sandbox to closed-alpha to paid pilot, working with the NEXT engineers to ultimately deliver production ready solutions.Define and run accuracy validation against Fifty5Blue's panel and against customer benchmarksDocument methodologies clearly for sign off and, where applicable, for clients and industry accreditation bodies (MRC, JICs, IAB) to review.Cross-functional collaborationWork alongside product managers and software engineers in 6-week sprint cadence.Partner with Fifty5Blue's central data-science team where required to pass successful products back to core business for scalingBrief leadership and design partners on technical results in language they can act on.CAPBILITIES AND EXPERIENCEWhat You’ll Bring (Required)Extensive applied data science / statistics / ML experience, with significant time on measurement, panel, advertising, or media-related data.Strong methodological foundation: causal inference, calibration, weighting, panel statistics, model validation, marketing science techniquesComfort working with imperfect data and evolving requirements – balancing panel sparseness, consent constraints and first-party data access while rapidly exploring new ideasPreferred ExperienceDirect experience with TV/cross-media measurement panels, big-data calibration, audience modelling, sales and conversion data.Recent experience applying modern AI techniques (e.g. foundation models, LLMs, embeddings or synthetic data) to real-world measurement or analytics problemsFamiliarity with the industry accreditation landscape (MRC, JIC, IAB) for measurement methodologies.Proven ability to work independently with limited oversight – you’ll be working closely with the rest of the cross-functional team, but will be one of two data science experts. You may report to someone without direct data science experienceHow we workFifty5Blue’s core values are: Clarity, Independence, and Impatience. At NEXT, we live those values – moving at pace, with high degree of transparency and collaboration, and a commitment to testing and failing fast. We move in weeks not months, days not weeks; we make decisions quickly and in the open; we celebrate good kills as much as good launches.