Job Description We are currently looking for a skilled Principal App Engineer (m/f/d) with a passion to assume leadership responsibilitie s to support us in building the fastest & most intuitive shopping app using a brand-new tech stack onsite in Hamburg or Berlin ! As a Principal position, this role requires a high degree of autonomous working and reports directly to the Director of Engineering. You will be the primary technical lead responsible for all app teams, driving technical discussions and ensuring our solutions are robust and forward-thinking. The App & Web Team constantly improves the App, Mobile Website and Desktop Website. These big-scale products are each visited by over 11M active users every month. The team’s focus is to provide our customers the most inspiring, convenient, intuitive, and easy-to-use shopping experience. They constantly challenge themselves to raise the bar of what is “state of the art” in customer-facing products. What you will do Build and maintain a high-quality mobile application using Flutter for iOS and Android platforms Participate as a solution architect from the very beginning of new projects; you will not just implement changes but think them through deeply and be responsible for the i mplementation across all stacks. Gain significant exposure to other teams, such as Shop Backend and Webstacks, to align solutions and drive the tech stack of all teams forward. Drive technical discussions forward with the team and lead architectural alignment. Lead by example and set coding standards, review pull requests and mentor other engineers in the team. Empower the team to deliver mission-critical features in quality & time. Contribute to architectural decisions across multiple stacks. Closely collaborate with Product Managers, Designers, Testers and other stacks (Backend and Web). Introduce new technologies, tools or processes that improve developer productivity and product quality. Debug performance and reliability issues across the stacks Who you are 8 years of programming experience, with at least 3 years of native or hybrid App development experience. Expert-level Dart & Flutter knowledge. CI/CD experience - Google Play Store, App Store deployments (fastlane, GitHub Actions or similar) Experience with Unit and Golden Tests. Experience of performance optimisation and profiling (using Flutter DevTools). Mobile native experience - iOS or Android. Experience with monitoring tools - Firebase Crashlytics, Sentry, DataDog etc. Figma knowledge. Experience using AI (e.g. Copilot or Cursor) to speed up coding experience. Experience with Backend development. Mobile automated testing. Excellent problem-solving: You can solve conceptual, non-standard problems and exercise solid judgment based on analyzing multiple sources of information. High autonomy and ownership: You are motivated, take matters into your own hands, and can lead a complex project or process with little oversight from your manager. Strong communicator: You can communicate transparently, honestly, and effectively with both technical and non-technical stakeholders (e.g. Product, Design). Team player: You actively share knowledge, inspire other team members, and aim to fulfill team goals. Nice to have Experience in Web Development DevOps experience (e.g. CI/CD pipelines, AWS) gRPC experience Firebase experience Open-source experience Benefits Hybrid working Company Pension Plan Fresh fruit every day Sports courses Exclusive employee discounts Free drinks Language courses Company parties Help in the relocation process Mobility subsidy State-of-the-art technology Central Location Flexible Working Hours Dog-friendly office AY Academy Feedback Culture Job Bikes *Please find free fruits, drinks and coffee in our lovely Hamburg Office / HQ YOU ARE THE CORE OF ABOUT YOU. We take responsibility for creating an inclusive and exceptional environment where all genders, nationalities and ethnicities feel welcomed and accepted exactly as they are. We believe that a diverse workforce essentially contributes to the ABOUT YOU culture. In order to maintain talent and diversity, we emphasize the care for physical health, mental health and overall well-being. Our values and work ethics essentially contribute to our brand mission: empower acceptance and shape an inclusive, fair and circular fashion culture. We are looking forward to receiving your application – preferably via our online application portal! Thus, we can ensure a faster process and for you it is very easy to upload your application documents. :-)