Principal Applied Scientist / Lounge by Zalando (all genders)

Role: As a Principal Applied Scientist at Lounge by Zalando, you will work across teams focusing on recommendation systems and agentic development. You will build customer-facing fashion assistants and personalized landing pages, defining evaluation metrics and working hands-on with custom ML models and LLM-based solutions. This is an individual contributor role requiring strong coding skills and the ability to contribute to production environments at a fast pace. Responsibilities: - Use LLM APIs to create fashion assistants for customers. - Develop and improve machine learning applications, including personalized recommendation systems. - Translate business challenges into research questions and lead end-to-end applied science strategy (model selection, problem formulation, training, and inference). - Develop and implement evaluation frameworks to assess initiatives, analyze customer behavior, and evaluate business performance. - Utilize AI coding tools to deliver software efficiently. Qualifications: - At least 3 years of hands-on industry experience building and deploying scalable, high-performance recommendation or search solutions. - At least 5 years of software engineering experience using Python. - Strong knowledge of machine learning and statistics, with a track record in empirical science and online A/B testing. - Extensive experience with deep learning, gradient boosting trees, and vector search (e.g., PyTorch, TensorFlow, CatBoost, FAISS). - Practical experience with large-scale data processing and deploying models to production (e.g., Databricks, Spark, Flink, Beam, Sagemaker, Kubernetes, REST APIs). - LLM application development and evaluation experience is highly desired. What We Offer: - 27 days of holiday per year (increasing up to 30 days). - Hybrid working model with up to 60% remote work. - Work from abroad for up to 30 working days per year. - Employee shares program and product discounts (40% off Zalando, 30% off Lounge by Zalando). - Relocation assistance, family services, and health/wellbeing support. - Access to training platforms and professional development.