# Staff Data Scientist, Experimentation at Wallapop

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> Responsibilities: - Define and lead the company-wide experim

- **Company:** Wallapop (https://jobs.trythestack.co/companies/wallapop)
- **Location:** Barcelona, Spain
- **Work arrangement:** On-site
- **Employment type:** Full-time
- **Experience level:** 10+ years
- **Visa sponsorship:** Offered, according to the listing
- **Key skills:** Experimental Design, Statistical Inference, A/B Testing, Causal Inference, SQL, Python, R, Variance Reduction, Hypothesis Development, Stakeholder Management, Product Analytics, Marketplace Optimization
- **Posted by employer:** 2026-07-03
- **Added to The Stack:** 2026-07-04
- **Status:** May no longer be active (posted more than 60 days ago)
- **Apply:** https://job-boards.eu.greenhouse.io/wallapop/jobs/4917916101 (the employer's own application page)
- **Human page:** https://jobs.trythestack.co/jobs/staff-data-scientist-experimentation-wallapop

## About the role

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.

## Responsibilities

Lead the evolution of Wallapop's experimentation practice by defining company-wide standards and improving statistical rigor. Partner with cross-functional teams to design and analyze experiments that drive product decisions across the marketplace.

## Requirements

Requires 8+ years of experience in data science or causal inference, with at least 4 years focused on experimentation. Proficiency in SQL and Python or R is essential, along with a proven ability to influence senior stakeholders.

## FAQ

- **Is this Staff Data Scientist, Experimentation role still open?** It was posted on 2026-07-03. Listings more than 30 days old may no longer be active, so check Wallapop's site before applying.
- **Does Wallapop offer visa sponsorship?** This listing is marked as offering visa sponsorship. Eligibility rules are set by the employer, so check the details on Wallapop's site.
- **Where is this role located?** The listing gives the location as Barcelona, Spain. It is marked on-site.
- **What skills does this role ask for?** The listing names: Experimental Design, Statistical Inference, A/B Testing, Causal Inference, SQL, Python, R, Variance Reduction, Hypothesis Development, Stakeholder Management, Product Analytics, Marketplace Optimization.

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