Senior Marketing Data Scientist / MMM Specialist Location: London (Hybrid Working) Duration: Minimum 12 month contract long term extensions - Project scope scheduled for the next 3/4 years. Start Date: ASAP We have an excellent opportunity for a Senior Marketing Data Scientist/MMM Specialist to join a multinational FMCG brand in London. Hybrid working, initial 12 month contract opportunity to extend long-term & start date ASAP. Role Summary: Lead data activities including extraction, transformation, analysis, and validation to support Marketing Mix Modelling (MMM). Build, enhance, and validate models to analyze KPIs and guide budget optimization and scenario planning. Key Responsibilities: Extract, manipulate, and analyze datasets to prepare for modelling (Excel, SQL, Python, Pandas). Build and refine base models with clear variable rationale and KPI linkage. Create ROI workbooks, response curves, and optimization charts. Run scenarios for budget allocation and client objectives. Validate models for accuracy, suggest and test improvements. Required Skills & Experience: Proven experience with MMM development and implementation. Strong Python skills; familiarity with R for MMM. Expertise in regression modeling, statistical and ML techniques. Experience with probabilistic programming, Bayesian methods, PyMC and MCMC. Proficient in SQL and/or Spark for large-scale data mining. Solid understanding of statistical foundations and mathematical modelling. Familiarity with cloud-based frameworks; Azure preferred. Advanced degree (MS/PhD) in Data Science, Computer Science, Statistics, Applied Math, or related field. Strong Points: Deep technical specialization in optimization, simulation, and applied math. Ability to translate complex models into actionable business insights.