Senior Backend Developer PHP/Symfony - AI & E-Commerce (m/w/d) in Warendorf

Your career opportunity as SENIOR BACKEND DEVELOPER PHP/SYMPHONY – AI & E-COMMERCE (m/f/d) Is PHP/Symfony your foundation—and do you consider AI an integral part of modern software engineering? Then join us in further developing the backend of an e-commerce store with more than 3 million customers and over 140,000 products. At hygi.de, as a Senior Developer, you’ll take responsibility for architecture, sophisticated store features, and code quality—while also helping shape how we productively deploy AI coding tools and AI applications. YOUR ROLE As a Senior Backend Developer, you’ll work in our backend team alongside three other developers and collaborate closely with our Shop Team Lead. You’ll not only develop features but also actively help shape the architecture and technical standards. In doing so, you’ll bridge the gap between software engineering, AI, and business impact: You’ll apply AI tools effectively in the development process, evaluate new AI use cases for our online store, and ensure that these result in stable, economically viable solutions. YOUR RESPONSIBILITIES You’ll continue to develop our backend architecture using PHP 8.x and Symfony and make informed decisions regarding scalability, maintainability, and performance. You’ll design and develop sophisticated e-commerce features related to checkout, pricing logic, product catalog, search, and fulfillment. You’ll ensure high code quality through clean code, automated tests, code reviews, and CI/CD. You use AI coding assistants and agents such as Claude Code, Cursor, or GitHub Copilot for development, refactoring, testing, and documentation. Together with the team, you develop standards for AI-supported development workflows and critically review AI-generated code. You identify productive AI use cases for our online store—such as smart search, product data enrichment, recommendations, or process automation. You’ll translate business goals into technical solutions while keeping an eye on KPIs such as conversion rate, cart value, margin, and process costs. You’ll serve as a technical sparring partner for product owners, developers, and other departments, and share your knowledge with the team. WHAT YOU BRING TO THE TABLE At least 5 years of experience in backend development with modern PHP and Symfony In-depth knowledge of software architecture, e.g., DDD, modular monoliths, microservices, or event-driven architecture Very strong knowledge of MySQL, performance optimization, caching, and queuing Practical experience with AI coding assistants or coding agents A good understanding of when a technical solution is not only elegant but also economically sound Excellent German and good English skills A plus, but not required: Experience with LLM APIs, RAG, embeddings, vector databases, or agent-based workflows, as well as e-commerce systems and interfaces to ERP, payment, or logistics systems. Experience in mentoring or providing technical guidance to other developers is also welcome. OUR TECH STACK Applications: PHP 8.x, Symfony Data and Interfaces: MySQL, Redis, RabbitMQ Delivery and Operations: On-premises hosting, Git, CI/CD Collaboration: Jira and Confluence WHAT WE OFFER YOU A secure job at a rapidly growing e-commerce company Competitive compensation package, including a contribution to an employer-sponsored retirement plan 30 days of vacation Flexible work hours with flex time Personalized training and development opportunities Employee discounts on our entire product range Modern workspaces and a digital work environment Bike leasing for a sustainable commute Regular team events and group activities Free drinks, fruit, and snacks WHY HYGI.DE? hygi.de is a growing e-commerce business with more than 3 million customers and over 140,000 products. Around 300 employees are driving our company’s growth. We rely on digital processes, quick decision-making, personal responsibility, and creative ideas. In this role, you’ll actively help shape our technology and the collaboration between IT and business units. READY TO BUILD WHAT COMES NEXT? Would you like to join our team and make a difference with us? Then send us your application as a PDF to karriere@hygi.de. We look forward to getting to know you! About hygi.de hygi.de is the leading online store for medical devices, hygiene, and cleaning supplies in Germany. Since 2003, we’ve been continuously expanding our product range and offer our more than 3.2 million customers the industry’s largest selection, featuring over 140,000 products. Our success is built on the extensive expertise and passion of our approximately 300 employees. We are a diverse team with varied backgrounds, skin colors, sexual orientations, gender identities, ages, religions, disabilities, and worldviews—this is what makes our work culture so special, because we leverage our diversity to achieve extraordinary results! This human expertise is complemented by a modern digital infrastructure, streamlined decision-making processes, and a commitment to fostering innovation, shared responsibility, and team spirit. Contact karriere@hygi.de Location Telgte (near Münster) hygi.de GmbH & Co. KG Otto-Diehls-Straße 13–17 D-48291 Telgte www.hygi-unternehmen.de