Senior Principal Applied Scientist - ZMS (all genders)

Role: Senior Principal Applied Scientist – drive scientific vision and execution for the Bidding and Allocation engines within Zalando Marketing Services (ZMS). The ad‑tech system makes real‑time, high‑stakes decisions on thousands of candidate ads, requiring large‑scale Bayesian inference, value‑based bidding, incrementality allocation, reinforcement learning and multi‑objective optimization. Lead optimization at the intersection of high‑load low‑latency engineering, auction theory and mechanism design. Responsibilities: - Lead research and development of real‑time bidding and allocation algorithms, optimizing platform health, advertiser performance and user relevance. - Advance auction and mechanism design capabilities to ensure a fair, efficient and transparent marketplace. - Collaborate with product managers, engineers and analysts to translate complex business constraints into mathematical objective functions. - Drive the long‑term scientific and execution roadmap for ZMS Ad Tech bidding optimization together with engineers and ML scientists. - Mentor and grow senior team members, acting as a force multiplier for the scientific community. Qualifications: - PhD in Machine Learning with a strong publication record and industry experience. - Proven research excellence demonstrated by peer‑reviewed publications in computational advertising, auction theory, mechanism design, game theory or equivalent impact. - 10+ years of experience (principal level) optimizing complex systems through automated algorithms, especially in Ad Tech, marketplaces or related fields. - Deep expertise in optimization, control theory or reinforcement learning applied to bidding and budget pacing. - Expert knowledge of productionalizing ML models under ultra‑low latency constraints and large‑scale distributed systems. - Strong proficiency in Python and related stack; ability to architect scalable data pipelines for sparse, high‑dimensional advertising data. What We Offer: - 27 days holiday (up to 30 with seniority) plus 2 paid volunteering days. - Hybrid working model with up to 60 % remote and up to 30 days per year working from abroad. - Employee share program, 40 % discount on Zalando fashion & beauty products, 30 % discount on Lounge and external partner offers. - Relocation assistance (subject to agreement). - Family services, health and wellbeing options, mental health support and coaching. - Development opportunities via training platform and bi‑annual peer‑to‑peer review.