Senior Software Engineer - Machine Learning (all genders)

Role: Senior Software Engineer (Machine Learning) on the Lounge Assortment Optimisation team, which builds decision products for assortment planning and customer experience. The portfolio includes optimisation systems, forecasting products, and Generative AI solutions. Responsibilities: - Build and operate production systems for optimisation, forecasting, machine learning, and Generative AI use cases. - Design scalable data and ML pipelines using Python, Databricks, Spark, Airflow, and dbt, with clear data contracts and reliable failure handling. - Enable Applied Scientists to develop and evaluate models efficiently by providing reusable training, evaluation, deployment, and experiment-tracking capabilities. - Productionise models: define dependable inputs and outputs, automate deployment, monitor quality and performance, and make model behaviour traceable in production. - Develop and operate workloads in the appropriate execution environment: Databricks jobs for distributed data and ML processing, and Dockerised applications running as Kubernetes pods where needed. - Build operational dashboards, alerts, and runbooks so that users and engineers can understand system state, identify issues, and respond effectively. - Work with product and commercial partners to convert business rules and decision requirements into maintainable software components. - Raise the engineering bar through pragmatic standards for system design, testing, code review, CI/CD, observability, and operational ownership. Qualifications: - 3+ years of experience building and running data or ML systems in production, for example in MLOps, data engineering, ML platforms, or ML product development. - Write maintainable production Python and follow established software-delivery practices, including automated testing, code review, and CI/CD. - Strong software engineering fundamentals: reliability, scalability, observability, and maintainable system design. - Understand how cloud workloads are deployed and run, including AWS, Docker containers, and Kubernetes-based execution. - Communicate clearly with both technical and non-technical stakeholders and enjoy turning ambiguous problems into dependable systems. - Experience with Generative AI products, including LLM evaluation and monitoring, is a plus. Familiarity with AI-assisted development tools such as Codex, Claude Code, or Copilot is welcome. What We Offer: - Employee shares program - 40% off fashion and beauty products sold and shipped by Zalando, 30% off Lounge by Zalando, discounts from external partners - 2 paid volunteering days a year - 27 days of vacation a year to start for full-time employees - 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