Lead Data Scientist (Ad Tech)

TL;DR

Lead Data Scientist (Ad Tech): Building and optimizing a high‑performance, privacy‑respectful in‑house advertising ecosystem with an accent on ranking, targeting, and auction logic. Focus on designing objective functions, developing pacing and budget optimization models, and solving complex real‑time marketplace challenges.

Location: Hybrid (offices across Europe, e.g., Vilnius or Germany)

Salary: €90,100 — €132,500 per year

Company

Europe’s leading second-hand fashion platform connecting millions of members across 20+ markets.

What you will do

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

Requirements

• Strong applied machine learning and statistical skills.
• Experience with Ad Tech systems and optimization problems.
• Proficiency in Python and SQL (BigQuery is an advantage).
• Proven experience in ads ranking, auction systems, or recommendation systems.
• Solid written and spoken English

Nice to have

• Experience with real-time optimization environments and budget optimization.

Culture & Benefits

• Hybrid work model with 2 days in office recommended.
• Share options programme and comprehensive pension plan with 150% matching.
• 30 days of paid annual leave and workation opportunities (up to 90 days per year).
• Health, life, and disability insurance, plus digital mental health support.
• Home office budget of up to €540 and lunch benefits.
• Annual individual learning budget for professional growth.