THE ROLE & THE TEAM Lounge by Zalando is a rapidly growing part of Zalando, now turning over billions of euros each year. That said, there is so much untapped potential with respect to personalization and recommendation. You will be a Backend Engineer, working alongside data engineers and data scientists to build and evolve large-scale recommender systems. As the largest online fashion retailer in Europe, we require a skilled engineer who can contribute to the design, building, and maintaining high-performance, low-latency backend systems for our Machine Learning infrastructure at a global scale. You will contribute to areas related to the online inference and serving of our real-time personalization algorithms. This is a very good opportunity to build critical backend services that have a measurable impact on the business and the user experience. You will have significant input into architectural decisions, and the opportunity to direct them, helping to implement state-of-the-art ML recommender serving solutions. There are very few roles that offer this unique synthesis of backend system scale, performance, and ML complexity. Our team thrives on a multidisciplinary approach, and while this role is primarily focused on backend development, we highly value individuals who are adaptable and willing to contribute to other areas as needed, fostering a truly collaborative environment. INCLUSIVE BY DESIGN At Zalando, our vision is to be the leading pan-European ecosystem for fashion and lifestyle e-commerce - one that is inclusive by design. We only assess candidates based on qualifications, merit, and business needs. We welcome applications from people of all gender identities, sexual orientations, personal expressions, racial identities, ethnicities, religious beliefs, and disability statuses. We only want to know why you’re great for this role, so please avoid including your picture, age, and marital status in your CV as well. We want to provide you with a great candidate experience. Please feel free to inform us of any accommodations you may need, so we can best support and assist you throughout the hiring process. do.BETTER - our diversity & inclusion strategy: https://jobs.zalando.com/en/our-culture/diversity-and-inclusion WHAT WE’D LOVE YOU TO DO (AND LOVE DOING) Design & develop low-latency, high-load, real-time recommender systems end-to-end. Contribute to the evolution of our backend services, enabling faster integration and support for diverse machine learning algorithms. Champion engineering best practices, clean code, and maintainable architectures to ensure high-quality and robust systems. Participate in code reviews, technical discussions, and knowledge sharing sessions within the team to foster a culture of continuous improvement. Collaborate with brilliant Product Managers, Data Scientists, Engineers, and Analysts across Zalando to create positive customer impact together. Help to define our team's objectives. Continuously improve the self-organization of the team. WE’D LOVE TO MEET YOU IF You have 3 years of experience designing and developing highly available, high-load distributed systems, ideally using Java. You enjoy solving complex technical challenges and bring a strong analytical mindset to your work. You care about writing clean, scalable, and maintainable code, and follow solid engineering principles and best practices. You have experience with concurrent programming, such as multi-threading. You’re comfortable working close to the system, with knowledge of low-level programming, hardware-aware development, JVM internals, or the Java Memory Model. Experience with container technologies like Docker and Kubernetes, and cloud platforms such as AWS or GCP, is a nice plus. Familiarity with modern Java frameworks like Spring Boot or Dropwizard is also beneficial. 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 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 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 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 ABOUT LOUNGE BY ZALANDO Lounge by Zalando is an online outlet for fashion and lifestyle products in 17 European countries. We offer our members daily, time-limited sale campaigns with discounts of up to 75% off the recommended retail price. However, Lounge by Zalando is so much more than discounts. Our strength lies in our focus on fashion and lifestyle brands: from sought-after labels to niche brands, from famous international names to trendy luxury brands, we make sure to meet the fashion taste of all our customers, who are always on the hunt for the best products at the best prices. Working with our brand partners, we're pioneering innovative supply-chain and production processes and offer them an impactful and smart solution, creating a new way to shop for fashion - and a new way to sell it. https://www.zalando-lounge.de