Lead Data Scientist (AdTech)

TL;DR

Lead Data Scientist (AdTech): Developing an in-house advertising ecosystem for a second-hand marketplace with an accent on ranking, targeting, and budget allocation. Focus on building performance-first optimization systems, auction logic, and balancing advertiser value with user experience.

Location: Hybrid (Offices across Europe)

Salary: €86,600 - €117,200 gross per year

Company

Europe’s leading platform for second-hand fashion and a go-to destination for pre-loved items.

What you will do

• Own optimization logic for Ads systems, including ranking, targeting, pacing, and bidding logic.
• Design and iterate models for Ads delivery, prediction, scoring, and constrained optimization.
• Lead experimentation frameworks to define hypotheses and translate learnings into system behavior.
• Define objective functions that balance advertiser value, revenue, and user experience.
• Perform deep-dive diagnostics on system performance, auction dynamics, and supply-demand imbalances.
• Partner with engineering and product teams to implement models into reliable production systems.

Requirements

• Strong applied machine learning and statistical skills.
• Experience with Ad Tech systems and optimization problems.
• Proficiency in Python and SQL; BigQuery experience is an advantage.
• Strong product and business judgment.
• Ability to operate effectively in ambiguous, evolving domains.
• Solid written and spoken English

Nice to have

• Experience in ads ranking or auction systems.
• Experience with pacing, budget optimization, or recommendation systems.
• Experience with relevance modeling in real-time optimization environments.

Culture & Benefits

• Share options programme and Collective Defined Contribution Pension plan.
• Hybrid work model (2 days office recommended) and dog-friendly office.
• Annual individual learning budget for courses and certifications.
• Home office support including IT equipment and a €540 furniture budget.
• Workation policy: up to 90 days per year (21 days outside the EU).
• Mental health support, gym membership, and daily lunch benefit.