As Experimentation Lead, you will own Wallapop’s experimentation practice and raise the bar for evidence-based product decisions. You’ll define standards, governance, and a roadmap to accelerate reliable insights across Product, Engineering, Data Science, Analytics, and Leadership. You’ll act as hands-on expert and internal consultant on growth, personalization, search, trust & safety, monetization, and seller experiences. Join a mission-driven team shaping a connected trade ecosystem with scalable experimentation.

- Generous individual learning budget
- Private Health Insurance
- Relocation package
- 26 holidays per year
- Define and harmonize experimentation standards, vision, and governance across the company
- Lead the development of advanced statistical methods and guardrails to speed and improve decision quality
- Coach and partner with Data Analysts, Data Scientists, and PMs on hypothesis design, experiment setup, and metrics




- Build and deliver an experimentation curriculum, playbooks, and training for cross-functional teams
- Collaborate with Data/Analytics Engineering to improve data infrastructure and exposure logging
- Design experimentation approaches for search ranking, recommendations, personalization, marketplace dynamics, and monetization
- 8+ years in data science, product analytics, or causal inference
- at least 4 years focused on experimentation (design, inference, A/B testing, variance reduction)
- Strong SQL proficiency and experience with Python or R
- Proven ability to partner with Product and influence senior stakeholders
- Leadership experience building experimentation cultures and coaching teams
- strong business judgment
- coaching and mentoring
- cross-functional collaboration
- SQL
- Python or R

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📌 Staff Data Scientist, Experimentation - Wallapop (Barcelona)
🏢 Wallapop
📍 Barcelona