Wallapop

We're looking for passionate and curious Graduate Software Engineers ready to begin their engineering career through an immersive, 18-month rotational Full-Stack Graduate Program.

🎯 Responsibilities

1. Build and deploy features for systems serving millions of users
2. Rotate through three core engineering chapters over 18 months—Backend (Kotlin/Java), Frontend (React/Angular), and one mobile platform (iOS or Android)
3. Collaborate with senior and mid-level engineers for mentoring, code reviews, and skill development
4. Leverage AI developer tools (e.g., Copilot, Claude) as a standard part of your workflow
5. Participate fully in agile team routines including standups, planning, retrospectives, and code reviews
6. Actively identify learning blockers, ask questions, and share knowledge with peers

🛠️ Requirements

1. Recent graduate (University degree, Grado Superior, or equivalent); this is a first professional engineering role
2. Basic coding ability with experience building and debugging projects
3. Strong curiosity and drive to understand how systems work
4. Quick learner, able to adapt to new technologies and environments
5. Open to working across multiple technologies and platforms, not limited to one stack
6. Keen attention to quality and a motivation to build software for positive impact
7. Fluent English communication skills, with the ability to collaborate effectively in an English-speaking environment

🤗 We Offer

1. Permanent contract from day one
2. Structured 18-month rotational program with progressive ownership
3. Dedicated mentor support for each chapter, plus a stable program manager
4. AI-focused onboarding to enable fast contributions
5. A clear development path to Full-Stack Engineer upon completion
6. Competitive graduate salary
7. Generous individual learning budget (2k/year)
8. Free office meals with a variety of lunch options
9. Group/individual language lessons (English, Catalan, Spanish)
10. Private health insurance
11. Flexible working hours, including intensive Fridays
12. Flexible salary deductions (childcare, meals, transport)
13. Gym and wellness plan, with physiotherapist available
14. Referral program and charity donation initiatives
15. Bonuses for weddings and newborns
16. Tax income support
17. Monthly plan for free shipping, bumps, and home pick-up on company services
18. Anniversary gifts and birthday surprises
19. Monthly contribution towards home WiFi
20. One-time payment to support home office setup
21. Relocation package and visa sponsorship if eligible
22. 26 holidays per year
23. Choice of top-tier hardware (latest Apple or Windows)

📝 Hiring Process

1. Introductory call with Talent Acquisition to discuss your background, motivation, and expectations (45-60 minutes)
2. In-person assessment centre (mid-July), including collaborative exercises and a chance to meet the team

We're looking for an experienced Staff Data Scientist, Experimentation to lead and evolve experimentation practices across the organization, drive statistical excellence, and support evidence-based product decisions.

🎯 Responsibilities

1. Define experimentation strategy, vision, and roadmap
2. Establish company-wide standards for experiment design, prioritization, guardrail metrics, and governance
3. Introduce and own advanced statistical methodologies (CUPED, sequential testing, network effect measurement, quasi-experimental designs, incrementality measurement)
4. Advise and coach Data Analysts, Data Scientists, and Product Managers on hypothesis development, experiment design, and success metrics
5. Build and deliver training programs, playbooks, and office hours for experimentation education
6. Collaborate with Data Engineering and Analytics Engineering to improve experimentation infrastructure and data practices
7. Develop experimentation approaches for marketplace features including search ranking, recommendations, personalization, supply-demand dynamics, trust & safety, seller growth, and monetization

🛠️ Requirements

1. 8+ years of experience in data science, product analytics, or causal inference, with at least 4 years deeply focused on experimentation (including experimental design, statistical inference, A/B testing, and variance reduction)
2. Strong proficiency in SQL and experience using Python or R
3. Proven ability to partner with Product teams and influence senior stakeholders using strong business judgment
4. Experience building experimentation cultures and coaching PMs and analysts
5. Excellent communication skills

➕ Nice to have

1. Experience with Amplitude
2. Background in marketplaces, e-commerce, consumer internet, or two-sided platforms
3. Experience with recommendation or search systems

🤗 We offer / Benefits

1. Generous individual learning budget (2K per year)
2. Free office meals with a variety of lunch options
3. Group and individual English, Catalan, and Spanish lessons during working hours
4. Private health insurance
5. Flexible working hours and intensive Fridays
6. Flexible remuneration options (kindergarten/food/transport checks)
7. Gym & wellness plan, including on-site physiotherapist
8. Referral program and charity donation initiatives
9. Bonuses for weddings and newborns
10. Support with tax income (Renta)
11. Monthly product advantages
12. Work anniversary gifts and birthday surprises
13. WIFI contribution in monthly payroll
14. One-off payment to support home office setup
15. Relocation package with monetary support and legal advice, plus visa sponsorship if needed
16. 26 holidays per year
17. Top hardware of your choice (latest Apple or Windows devices)

💼 Hiring Process

1. Intro call to discuss your background, motivation, and expectations
2. Technical task submission within 5-7 days to showcase expertise
3. Expertise interview focused on core skills and delivery ability
4. Stakeholder interview assessing collaboration in a cross-functional context
5. Culture interview focused on alignment with the organization's mission
6. Offer discussion and confirmation