Senior Fullstack 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 across 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. About the team We’re the Developer Platform team within the AI & Cloud Platform department, and we build the foundations the other engineering teams at JTL rely on. Our work spans three areas: Developer Enablement: engineering standards, shared tooling, CI/CD, and internal developer documentation that make product teams more productive. Cloud Platform Enablement: self-service building blocks for our first-party apps, from deployments and infrastructure to identity and API management. External Developer Relations: public developer documentation, SDKs and CLIs, our public APIs and API gateway, and developer community and events. AI enablement is a major focus for our department and our team: most of the platform features we ship are designed AI-first. Your responsibilities You work on the platform topics that matter most right now. Our focus shifts each quarter depending on where the company needs it most — sometimes frontend, sometimes backend, sometimes infrastructure You develop standards, guidelines, and best practices for frontend and backend at JTL You create and maintain templates, boilerplates, and libraries that help other teams work more productively and efficiently You support the bootstrapping of new projects, so our standards and toolchains are applied from the start You regularly evaluate new technologies and assess their value for our landscape Your profile You have several years of professional experience in fullstack development You are strong in one stack and solid in the other: React and TypeScript on the frontend, .NET 8 / C# on the backend Frontend: component-based development and design systems (Storybook, TailwindCSS), state management and data fetching (e.g. TanStack Query), modern build tools (Vite, turborepo, pnpm), and testing (Vitest, Jest, Playwright) Backend: CQRS and Domain-Driven Design (DDD), API development with FastEndpoints, and familiarity with GraphQL — ideally having designed a GraphQL API You are confident with Docker and common containerisation workflows, and with Git and collaborative workflows (pull requests, code reviews) You communicate clearly in writing and speech — a big part of the role is driving standards and best practices across teams You have a solid understanding of and genuine interest in AI development, since most of the platform features we ship are designed AI-first "You have business-fluent English (written and spoken) and good German skills Nice to have Terraform and hyperscalers, preferably Azure Micro-frontends CI/CD pipelines (GitHub Actions) Basic Kubernetes and Helm Infrastructure as Code (IaC), GitOps, and experience with 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 Ergonomic workspace allowance for your home office setup Regular team events, company-wide gatherings, and summer and Christmas parties to stay connected as a remote-first company EGYM Wellpass and JobRad subsidy Financial benefits including capital-forming payments (Vermögenswirksame Leistungen) and a 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!