Senior Marketing Data Analyst in London

Join to apply for the Senior Marketing Data Analyst role at Back Market. We are here to help make tech reliable, affordable, and better than new. Back Market is a global marketplace for refurbished devices, helping lower our collective environmental impact by providing trustworthy, affordable tech with 92% fewer carbon emissions than new.

Role Overview

As a Senior Marketing Data Analyst – Performance Marketing at Back Market, you will play a critical role in measuring and optimizing the incremental impact of our digital marketing investments. You will design and implement advanced incrementality measurement frameworks across performance marketing channels, including Paid Search, Shopping, PMAX, SEO, App campaigns, Meta, TikTok, Affiliates and Podcast. Leveraging causal inference techniques such as conversion lift studies, geo experiments, and synthetic control, you'll provide data‐driven insights that directly inform budget allocation, campaign strategy, and growth decisions.

Key Responsibilities

• Performance Marketing Impact Measurement
  • Design and execute incrementality measurement approaches (e.g., geo experiments, conversion lift studies, holdouts) to evaluate the true impact of digital marketing channels.
  • Build models to quantify incremental return on ad spend (iROAS), channel lift size and measure cross‐channel interactions.
  • Develop frameworks to continuously monitor and optimize campaign performance based on causal impact rather than last‐click attribution.
  • Collaborate with channel managers to translate insights into bidding strategies, budget reallocations, and creative optimizations.
• Causal Inference & Advanced Analytics
  • Apply state‐of‐the‐art causal inference methods to assess the impact of paid media strategies.
  • Create scalable and automated measurement pipelines in partnership with data engineering teams.
  • Contribute to the development of media mix modeling (MMM) frameworks to complement incrementality experiments.
• Predictive Modeling & Optimization
  • Build predictive models for audience segmentation, conversion propensity, lifetime value (LTV), and bidding optimization.
  • Use time‐series modeling and forecasting to predict performance trends and seasonality effects.
  • Ensure statistical rigor through robust model validation, assumption testing, and experimentation best practices.
• Cross‐Functional Collaboration & Communication
  • Partner closely with performance marketing, finance, data engineering, and product analytics teams to build the experimentation calendar, align on measurement methodologies and KPIs.
  • Present complex analytical findings and experiment results to both technical and non‐technical audiences, influencing marketing strategy and budget decisions.
  • Champion a culture of incrementality testing and data‐driven decision‐making within the marketing organization.

Requirements & Skills

• 4+ years of experience in marketing analytics, data science, or experimentation roles, preferably within performance marketing teams.
• Proven expertise in incrementality measurement techniques.
• Strong proficiency in SQL and Python, including libraries for statistical modeling.
• Hands‐on experience analyzing performance marketing channels.
• Familiarity with A/B testing, media mix modeling, and attribution modeling frameworks.
• Experience working with large‐scale marketing datasets and visualization tools.
• Excellent communication skills and a proven track record of translating complex data insights into business impact.
• Strong analytical rigor and judgment, including critical thinking and problem‐solving skills.

Job Details

• Seniority level: Mid‐Senior level
• Employment type: Temporary
• Job function: Information Technology
• Industries: Internet Marketplace Platforms