Data Scientist – Experimentation Framework - Harnham

Senior Experimentation Data Scientist (Contract) Contract Length: 3 months Day Rate: £650-£700 per day (Inside IR35) Location: London - Hybrid (2 days per week onsite) Overview We are supporting a leading eCommerce business in the search for a Senior Experimentation Data Scientist to deliver high-impact experimentation across logistics and operational initiatives. This role is explicitly not product-focused and will centre on experimentation relating to promotions, operational efficiency, and logistics performance. This is a fast-moving engagement with tight timelines, requiring someone who can hit the ground running and operate autonomously within a squad-based delivery model. Key Responsibilities • Design and execute experimentation frameworks focused on logistics and operational use cases • Lead A/B testing and controlled experiments to evaluate promotional and operational changes • Ensure analytical robustness through sense-checking data, assumptions, and outputs • Work closely with engineers, analysts, and operational stakeholders within a squad environment • Translate experimental outcomes into clear, actionable recommendations for the business • Operate independently while maintaining strong collaboration across technical teams Essential Technical Requirements • Advanced SQL (including joins, validation logic, and data interrogation) • Strong Python for analysis and experimentation workflows • Experience working with Google BigQuery or comparable cloud data platforms Experimentation Expertise • Proven experience designing and building experimentation frameworks • Strong grounding in experimental design, statistical validity, and bias mitigation • Confident explaining experimental approaches verbally, not just via documentation Ideal Contractor Profile • Senior-level experimentation data scientist with strong commercial awareness • Comfortable working at pace in short, delivery-focused contracts • Able to work independently with minimal oversight • Confident partnering with highly technical teams • Well-prepared, pragmatic, and delivery-oriented • Comfortable operating within tight timelines and changing priorities Skills Desired Skills and Experience Experimentation Design & A/B Testing Advanced SQL (joins, validation, optimisation) Python for Data Analysis Google BigQuery Statistical Analysis & Inference Data Quality & Sense Checking Operational & Logistics Analytics Stakeholder Management Agile / Squad-Based Delivery Experience Senior-level experimentation data scientist within eCommerce or operational environments Designing and building experimentation frameworks end to end Delivering logistics or operations-focused experiments (non-product) Working independently on short, high-impact contracts Partnering with highly technical teams under tight timelines How To Apply If you have experience building experimentation frameworks and thrive in dynamic, high-visibility roles, we’d love to hear from you. Apply now by sending your CV and availability to Atif Ahmad. #Jobster