Senior Backend Engineer - Developer Platform (f/m/d)

Your mission JTL is one of the leading providers of e-commerce software in the German-speaking region, with around 450 employees across the group and more than 50,000 customers from a wide range of industries. We build scalable, flexible solutions for the future of online retail – from ERP systems to shop and marketplace integrations. About the Team We are the Developer Platform team within the AI & Cloud Platform department. We build the foundations that enable JTL’s engineering teams to work efficiently and deliver high-quality products. Our work focuses on three key areas: Developer Enablement: Engineering standards, shared tools, CI/CD, and internal developer documentation that help product teams become more productive Cloud Platform Enablement: Self-service building blocks for our first-party applications, covering everything from deployments and infrastructure to identity management and API management External Developer Relations: Public developer documentation, SDKs and CLIs, our public APIs, the API gateway, as well as developer communities and events AI enablement is a major focus of our department and team: Most platform features we deliver are designed with an AI-first mindset. As a Backend Engineer, you will primarily contribute to the first two areas: Developer Enablement and Cloud Platform Enablement. Your Responsibilities Develop API solutions based on FastEndpoints and support the evolution of JTL’s company-wide GraphQL API where your expertise is needed Define and establish backend development standards, guidelines, and best practices across JTL’s engineering teams Create and maintain templates, boilerplates, and libraries that enable other teams to work more efficiently and productively Build and evolve cloud platform components, including self-service deployments, infrastructure using Terraform and Azure, and the central API gateway Ensure robust, maintainable, and scalable software architectures through the use of .NET 8, CQRS, and Domain-Driven Design (DDD) Support teams in adopting new standards and practices, as well as bootstrapping new backend projects. Regularly evaluate new technologies (e.g. SignalR) and assess their potential value for our backend ecosystem Your profile Several years of experience in backend development with a strong focus on modern .NET technologies, particularly .NET 8 Strong understanding of software architecture principles, including CQRS, Domain-Driven Design (DDD), and modern development patterns and libraries such as FastEndpoints and Mapster Experience designing and developing GraphQL APIs and working with event-driven architectures and messaging systems, ideally with Azure Service Bus Hands-on experience with NoSQL databases, especially Azure Cosmos DB, and building reliable, well-tested software using frameworks such as XUnit and Shouldly Confident working with Docker, containerization workflows, and cloud infrastructure, ideally on Microsoft Azure, including experience with Terraform Strong knowledge of Git and collaborative development workflows, including pull requests, code reviews, and engineering best practices Strong interest in AI-driven product development and enthusiasm for building AI-first solutions Excellent communication skills and the ability to drive technical standards and best practices across teams. Fluent in English, with good German communication skills Nice to have: Experience with SignalR, GitHub Actions, Kubernetes, Helm, Infrastructure as Code (IaC), GitOps, and Argo. Why us? Remote-first within Germany, with the option to work remotely from eligible countries for up to 180 days per year Meal allowance of up to €115 net per month Support for setting up an ergonomic home office Regular team events, company-wide gatherings, and summer and Christmas celebrations EGYM Wellpass and JobRad subsidy Employee savings benefits and company pension scheme About us JTL is one of the leading providers of e-commerce software in the German-speaking region – with around 450 employees across the group and 50,000 customers from a wide range of industries. We develop scalable, flexible solutions for the online retail of the future – from ERP systems to shop and marketplace integrations. Fairness and respect are part of our everyday practice. Are you committed, curious, and eager to work in a team while taking on responsibility? Are you looking for a job where Monday isn’t the worst day of the week? Then we look forward to receiving your application!