Staff Data Scientist, Experimentation at Wallapop

on-site · full-time · Visa sponsorship

Responsibilities:
- Define and lead the company-wide experimentation vision, roadmap, standards, and governance.
- Set and own statistical methodology: introduce advanced techniques (CUPED, sequential testing, network-effect measurement, quasi-experimental designs) to reduce decision latency.
- Partner with Product, Engineering, Data Science, Analytics, and Execs to design, prioritise, run, and interpret experiments across marketplace areas (search, recommendations, personalization, monetization, trust & safety).
- Build enablement programs: create curriculum, playbooks, training, and office hours to raise experimentation maturity across teams.
- Improve platform and tooling: collaborate with engineering to enhance exposure logging, experiment infrastructure, and quality standards for data.

Requirements:
- 8+ years in data science, product analytics, or causal inference, including ≥4 years focused on experimentation and A/B testing.
- Strong SQL and Python or R skills; experience with experimentation platforms and exposure logging practices (e.g., Amplitude Experiment or equivalents).
- Deep knowledge of experimental design, statistical inference, variance-reduction techniques, and causal methods for marketplaces.
- Proven ability to influence senior stakeholders, coach teams, and scale best practices across an organisation.
- Excellent communication, teaching skills, and experience working cross-functionally in product-driven environments.