Principal App Engineer

We are currently looking for a skilled
Principal App Engineer (m/w/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.

• Flutter
• Datadog

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 implementation 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
• Täglich frisches Obst
• Sportkurse
• Freier Zutritt zur
• Exklusive Mitarbeiter Rabatte
• Kostenlose Getränke
• Sprachkurse
• Kostenloser Laracasts Account
• Company Events
• Relocation Unterstützung
• Mobilitätszuschlag
• State-of-the-art Technologien
• Zentrale Lage
• Betriebliche Altersvorsorge
• Hunde erlaubt
• AY Academy
• Feedbackkultur
• Firmenfahrrad