Principal Applied Scientist

THE ROLE & THE TEAM
As a Principal or Senior Applied Scientist at Zalando Lounge, you will foster data-driven decision-making by designing experimentation frameworks in key areas of our business and analysing complex A/B tests. You will serve as an expert on causal inference and statistical modelling. Together with fellow economists on our team, you will participate in wide research efforts that impact company strategy and product development. You will collaborate with other applied scientists, data analysts, product managers, software developers, data engineers, and commercial stakeholders.
Lounge by Zalando is an online shopping club for fashion and lifestyle products in 13 European countries. We are the fastest growing sales channel of Zalando, generating approximately 15% of total Zalando Group revenue. Our rapid growth creates numerous research opportunities in diverse areas, such as pricing, campaign creation and customer experience.
Find out more about our team here: https://jobs.zalando.com/en/what-we-do#job-categories

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)

• Design experimentation frameworks in new areas, focusing on key performance indicators (KPIs), units of randomization, statistical power analysis, and variance reduction.

• Design and carry out experiments in complex cases, such as when straightforward designs would generate substantial Stable Unit Treatment Value Assumption (SUTVA) violations or when the relationship between short-term and long-term effects is non-trivial.

• Apply quasi-experimental methods to observational data, establishing indications of causal relationships to inform product development and further experimentation.

• Use economic modelling and first-principle reasoning to guide business decisions.

• Provide egoless, constructive scientific feedback to peers and coach junior colleagues.

• Set broad scientific roadmaps across the division and bring a significant industry track record alongside scientific leadership experience (required for candidates considered at the Principal level).

WE’D LOVE TO MEET YOU IF

• You hold a Ph.D. in Economics with an emphasis on quantitative research methods, alongside at least two years of post-Ph.D. experience.

• You possess deep expertise in experimentation and quasi-experimental research methods, such as Double Machine Learning (DML) and difference-in-differences.

• You demonstrate strong general scientific problem-solving skills and the ability to communicate analytical insights clearly to both technical and non-technical audiences.

• You are proficient in Python and SQL, with experience using Machine Learning methods, frameworks (scikit-learn, PyTorch), Jupyter Notebooks, Airflow, Data Build Tool (DBT), PySpark, Databricks, and Git.

• You have experience with the estimation of heterogeneous effects, such as causal forests.

• You regularly use AI-based analytical tools and maintain a mindset of constant exploration regarding new developments in this field.

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

Please note: All applications must be completed using the online form. We do not accept applications via email.