Senior Principal Applied Scientist - ZMS (all genders)

THE ROLE & THE TEAM As a Senior Principal Applied Scientist, you will drive the scientific vision and execution for the Bidding and Allocation engines within Zalando Marketing Services (ZMS). Every time a customer interacts with Zalando, our ad tech system must make high-stakes decisions in real-time. The system evaluates thousands of candidate ads, predicts performance metrics, and executes sophisticated auction logic to decide which ad to show and at what price. Every second, we process tens of thousands of requests where the intersection of market dynamics and machine learning creates unique challenges. In this position, you will lead our optimization efforts at the frontier of high-load low-latency Engineering, Auction Theory, and Mechanism Design. The technical scope covers Large Scale Bayesian Inference, Value based Bidding, Incrementality-based Allocation, Reinforcement Learning, and Multi-Objective Optimization. You will be instrumental in evolving our auction mechanisms to balance advertiser ROI with a premium customer experience INCLUSIVE BY DESIGN If you think you have what it takes, we encourage you to apply even if you don't meet every single requirement. You may just be the right candidate for this or other roles! At Zalando, our vision is to be the leading pan-European ecosystem for fashion and lifestyle e-commerce – one that thrives on diversity and is truly inclusive by design. We believe that diverse teams fuel innovation and creativity, and we actively seek out talent from all backgrounds. We actively seek to reduce bias in our hiring and employment processes, focusing on your qualifications, skills, and contributions. To support this, we kindly ask that you refrain from including personal details such as your photo, age, or marital status in your CV, ensuring a fair and equitable evaluation based solely on your abilities and potential. We are committed to providing an exceptional and accessible candidate experience for everyone. If you require any accommodations to support you throughout the hiring process, please let us know – we are here to assist you. Discover more about our commitment to creating a diverse and inclusive workplace: https://jobs.zalando.com/en/our-culture/diversity-and-inclusion WHAT WE’D LOVE YOU TO DO (AND LOVE DOING) Lead the research and development of our real-time bidding and allocation algorithms, optimizing for long-term platform health, advertiser performance, and user relevance. Advance our 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 in collaboration with Engineers and ML Scientists and foster a culture of technical excellence. Mentor and grow senior level members of the team, acting as a force multiplier for our scientific community. WE’D LOVE TO MEET YOU IF You have a PhD in Machine learning with a track record of publications and industry experience A proven track record of research excellence, evidenced by peer-reviewed publications in relevant fields such as Computational Advertising, Auction Theory, Mechanism Design, or Game Theory (please include these in your application) and/or equivalent applied industry impact track At least 10+ years of experience (commensurate with Principal level) in optimizing complex systems through automated algorithms, specifically within Ad Tech, Marketplaces, or related fields. Deep theoretical and technical expertise in optimization, control theory, or reinforcement learning applied to bidding and budget pacing. Expert knowledge of productionalizing ML models within ultra-low latency constraints and experience with large-scale distributed systems. Strong proficiency in Python and related stack, with a solid understanding of how to architect scalable data pipelines for sparse, high-dimensional advertising data. OUR OFFER Zalando provides a range of benefits, here’s an overview of what you can expect. Ask your Talent Acquisition Partner to learn more about what we offer. 27 days of holiday a year to start for full-time employees (+1 day for every calendar year up to 30 days) 2 paid volunteering days a year Hybrid working model with up to 60% remote per week, actual practice is up to each team to best support their collaboration Work from abroad for up to 30 working days a year Employee shares program 40% off fashion and beauty products sold and shipped by Zalando, 30% off Lounge by Zalando, discounts from external partners Relocation assistance available (subject to prior agreement) Family services, including counseling and support Health and wellbeing options (including Wellhub, formerly Gympass) Mental health support and coaching available Drive your development through our training platform and biannual peer-to-peer review