Backend Engineer

About the role

This is no ordinary job. We are working on what makes our society future-proof: education. For this, we are building paddy, the Agentic Operating System for Teaching & Learning. Our mission is to relieve teachers, improve learning outcomes, and increase the quality of instruction. Thousands of teachers and hundreds of thousands of learners are already using paddy. With strong investors behind us, we are growing fast. Our ambition is to build the European AI player for education. As a Backend Engineer, your focus is on backend engineering and architecture. You design APIs, data models, and services, and are responsible for them from understanding the user problem to operation in production. If necessary, you also bring features to the UI and thus keep an eye on the entire product. Tasks • Designing backend and architecture: You develop API-first services, data models, and system boundaries that make paddy reliable, maintainable, and scalable. • Shipping features end-to-end: You accompany features from the user problem through the backend and data model to the UI and bring them into production. • Implementing AI engineering: You build product functions with LLM APIs and agentic components. With tool calling, evals, error handling, and monitoring, you ensure reliable operations. • Ensuring production quality: You take responsibility for your systems and use testing, CI/CD, and observability to operate them stably. • Working close to the product: You talk to teachers, find the need behind their wishes, and make decisions with product and design instead of waiting for tickets. Qualifications • Backend and architecture experience: At least three years of experience in the development and operation of modern web applications, ideally with TypeScript, Node.js, and Next.js. You have designed and implemented APIs, data models, and backend services. • Technical foundation: You are secure in API design, databases, and asynchronous processes. Experience with CI/CD, Docker, Kubernetes, and monitoring is helpful. • Full-stack competence: You can move in React and Next.js and bring features to the UI yourself if necessary. • Practical AI engineering experience: You have implemented LLM-based features or agentic systems with APIs. You understand tool calling, typical model errors, and how to check the quality of such functions and observe them in operation. • Ownership and judgment: You deal with open requirements, find simple solutions to complex questions, and take responsibility for your systems in production. • Product thinking: You are interested in how users work and can connect technical decisions with their actual needs. • Languages: Fluent German and very good English. Benefits • Visible impact: You work on the most important future topic of our society, education. • 70,000 to 100,000 € gross annual salary, depending on your experience, plus equity (VSOP). • 100% remote work. If you prefer to come to the office, our modern office in Bielefeld is open to you. • Great creative freedom and ownership as well as direct cooperation with the founders and a strong product and engineering team. • A high budget, as long as the benefit is right. • Time and support for your development, with training budget, coaching, and clear development perspectives. • 30 vacation days and 50 € monthly tax-free benefit in kind. • Regular team events and offsites. • Strong backing by experienced investors and mentors. Our application process: 5 days If the calendars match, we can complete the entire process within five days. • Getting to know each other, day 1: In the first conversation, we see if it fits for both sides. If yes, we agree directly on your trial day. • Trial day with case study, day 4: You work with us on a real task and then present your result. • Conversation with our CEO, day 4: The conversation takes place on the evening of your trial day. • Team conversation, day 5: You get to know the engineers you will work with. • Decision, day 5: After the team conversation, we give you our final feedback. We look forward to meeting you. Tell us which problems you have solved, which decisions you have made, and which systems you have brought into production.