Senior Backend Engineer, Menu Personalization at Hellofresh

Work with HelloFresh in Warsaw and its HelloTech organisation, HelloFresh’s global technology backbone with more than 1000 people, building the digital products that power our end-to-end food experience. From meal kits and ready-to-eat meals to specialty offerings like pet food and premium meat & seafood, HelloTech creates the platforms that bring tailored food solutions to millions of customers every month. Our subscription-based, direct-to-consumer model relies on technology at every step, from customer-facing apps and personalization logic to pricing, forecasting, supply chain optimization, and initiatives that help reduce food waste. While our brands operate independently to serve distinct customer needs, they are united by shared platforms, data, and operational excellence built by HelloTech. HelloTech works in autonomous, cross-functional alliances, each owning a specific product or domain end to end. By working with our Warsaw office, you will help shape scalable, data-driven products used across our markets, working with a modern tech stack and international teams to continuously improve how people discover, order, and enjoy HelloFresh’s products, today and in the future. About the role: What's in the Box Do you have a drive for building high-performance, scalable systems and engineering low-latency, resilient services? You will contribute to a high-impact, cross-functional project focusing exclusively on menu personalization, acting as the bridge between sophisticated recommendation algorithms and the millions of customers who use HelloFresh daily. In this capacity, you will provide expert services to design, implement, and improve the robust microservices that serve personalized culinary options across our global markets. Collaborating in an autonomous, agile environment alongside Data Scientists and Machine Learning Engineers, you will facilitate the delivery of the backend architecture that powers our personalization engine. What you’ll do: The Recipe • Architect & Build: Deliver the core of our personalization engine by engineering high-availability Golang microservices that power real-time recommendations. You’ll build and optimize Python/FastAPI services that rank recipes using ML embeddings and sophisticated multi-objective optimization algorithms. • ML Operationalization: Partner closely with Data Scientists to translate complex statistical solutions and ML models into production-ready services. • System Evolution: Shape the future of our personalization platform by re-architecting legacy components into scalable, event-driven systems that can handle millions of requests globally. • Operational Excellence: Manage the full lifecycle of your services—from experimentation and local development to deployment and monitoring in production. • Experimentation Support: Design and implement the backend infrastructure required to execute A/B tests and measure the impact of new recommendation strategies. • Tech Stack Mastery: Work with state-of-the-art technologies including Kafka, Redis, SQS, FastAPI, Kubernetes, Docker, and PostgreSQL.Technical Guidance: Provide knowledge sharing and technical guidance to other engineering contributors through code reviews and architectural alignment. What you’ll bring: The Ingredients • Professional Experience: Long-term (5+ yrs) work experience in backend engineering, with a strong focus on building distributed systems and microservices. • Golang Expertise: Deep proficiency in Golang and experience with its ecosystem in a production environment. • Python Familiarity: Comfortable reading, understanding, and contributing to Python codebases. You don't need to be a Python expert, but should be willing and able to familiarize yourself with Python/FastAPI services, work with data processing libraries, and collaborate with Data Scientists who primarily use Python. • Distributed Systems: Proven track record with event-driven architectures and handling large-scale, heterogeneous datasets. • Cloud & DevOps: Hands-on experience with cloud infrastructure, container orchestration (Docker), and robust CI/CD pipelines. • Quality First: A strong foundation in software development best practices, including TDD, clean code, and Git. • AI-Assisted Development: Experience leveraging Generative AI tools (e.g., Claude, GitHub Copilot) to accelerate development and improve code quality. • Communication: Exceptional ability to translate technical architecture into business value for non-technical stakeholders and product partners. Above all, we are looking for individuals who will make HelloFresh better. We believe there are many different ways of developing skills and we love diverse experiences! So even if you don’t “tick all the boxes” but think you’d thrive in this role, we would really like to learn more about you. What we offer: The Toppings • Global collaboration at scale: Collaborate with experienced engineers and product partners across HelloTech’s international teams, in a culture of active knowledge sharing. • Technology with real-world impact: Build and operate modern systems at global scale, supporting 6+ millions of customers and complex supply chain operations. • Technical/Product/Design leadership: Drive best practices and influence architecture/design, quality, and ways of working in an autonomous, product-led setup. • End-to-end development/delivery: Drive decisions from problem definition to production, improving systems and enabling long-term scalability. • Access to workspace at Warsaw Centre Point. The hub offers modern facilities including showers, breakout zones, outdoor space, cycle parking, and refreshments (coffee, soft drinks, and fruit). Are you the missing ingredient? If this sounds like a tasty opportunity, we’d be excited to hear from you. We aim to review your profile and respond within 5 business days.