Principal App Engineer (m/f/d) - App & Web - onsite in Hamburg or Berlin

About the Company

ABOUT YOU SE & Co. KG is a leading fashion e-commerce company known for its inspiring, convenient, and intuitive shopping experience. Their mobile app and web platforms are visited by over 11 million active users every month.

Responsibilities

• 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
• Gain significant exposure to other teams to align solutions and drive the tech stack forward
• Drive technical discussions and lead architectural alignment
• Lead by example and set coding standards, review pull requests, and mentor other engineers
• Empower the team to deliver mission-critical features in quality and time
• Contribute to architectural decisions across multiple stacks
• Closely collaborate with Product Managers, Designers, Testers, and other teams
• Introduce new technologies, tools, or processes that improve developer productivity and product quality
• Debug performance and reliability issues across the stacks

Requirements

• 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
• 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 skills
• High autonomy and ownership
• Strong communication skills
• Team player

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