(Senior) Staff Engineer - Frontend (Web & Mobile) gesucht in Berlin

We are hiring a Staff / Senior Staff Frontend Engineer to lead the next evolution of our frontend platform, with a primary focus on our React Native mobile apps (iOS & Android) and supporting web (React) surfaces where they add value. This role goes beyond feature delivery: you will modernize frontend architecture, raise engineering standards, and help shape how frontend systems scale over time.

You will act as a force multiplier across teams, setting technical direction while staying hands-on where leverage is highest.

While this is a frontend-focused role, we value engineers with an end-to-end mindset. You'll work closely with backend, product, and design partners to deliver high-quality, reliable user experiences.

Your tasks

• Lead the modernization of frontend architecture, with an emphasis on mobile app architecture, performance, and scalability, while maintaining aligned web experiences where needed
• Evaluate and evolve frontend system design: application structure, state management, data flow, and runtime patterns
• Drive improvements in performance, reliability, accessibility, and overall user experience
• Establish and evolve best practices for frontend development, testing strategies, and build systems
• Reduce complexity and long-term maintenance cost through simplification, standardization, and better defaults
• Partner closely with backend, product, and design to define clean interfaces and deliver cohesive end-to-end experiences
• Improve frontend developer experience through tooling, shared patterns, and clear architectural guidance
• Contribute code where it has the highest leverage (foundational components, migrations, refactors)
• Mentor senior engineers and raise the bar through reviews, coaching, shared patterns, and architectural guidance

• 8+ years of professional software engineering experience (or equivalent impact)
• Deep, hands-on experience with React in production environments
• Strong experience with React Native and mobile app development (iOS and Android)
• Solid understanding of frontend system design - beyond UI implementation
• Experience leading large-scale refactors or platform transformations in existing codebases
• Strong understanding of performance, rendering behavior, and optimization techniques on web and mobile
• Experience working with design systems and component libraries at scale
• Practical knowledge of CI/CD for web and mobile applications
• Experience with frontend observability, monitoring, and performance measurement
• Ability to think in terms of platform leverage: shared primitives, safer defaults, tooling, and long-term maintainability
• Strong collaboration skills - comfortable working across teams, closely with backend experts, product and stakeholders
• Ability to balance technical quality with delivery and business constraints
• Strong written and verbal communication - able to explain trade-offs and influence decisions across teams If you enjoy shaping frontend platforms, improving performance and reliability at scale, and raising the bar across teams - we'd love to talk.

Join bonify, Germany's leading platform for credit scoring and financial management. We are on the mission to revolutionize the FinTech industry and make the credit score and financial data available and transparent for our users. We are seeking a talented Staff Engineer - Frontend (Web & Mobile) to join our dynamic team in Berlin., As part of the bonify team, you'll have: * The opportunity to take ownership from day one * The chance to thrive in a dynamic and flexible startup environment. * Access to extensive coaching and training programs through our personal development budget * 30 vacation days * Mental health support platform * Subsidies for BVG and UrbanSportsClub * 1:1 language classes in both German and English. The Company is committed to the principle that no employee or job applicant shall receive unfavourable treatment on grounds of age, disability, gender reassignment, race, religion or belief, sex, sexual orientation, marriage or civil partnership, pregnancy, and maternity. Please note, to be compliant with AML requirements, due to the specifics of fintech industries additional background checks are required (applicable only at the offer stage). If you're ready to make a meaningful impact in the world of FinTech and embark on an exciting career journey, apply now to join bonify!