When Thibault, the CTO of Payback, asked me to help with their mobile app, I was excited to contribute to a platform that helps French employees simplify and maximize their benefits.
I worked on enhancing the app's performance and user experience, implementing new features to better serve their diverse user base, and later contributed to both backend and web development.

Challenges & Solutions

• Optimized app performance: Reduced interaction response time from 1–2 seconds to ~200–300ms, significantly improving the mobile experience.
  • Replaced global state management (Redux) for transient states (e.g., loading, error, success) with TanStack Query.
  • Optimized rendering cycles by leveraging React.memo and useCallback to prevent unnecessary re-renders.
  • Implemented efficient data fetching strategies, including pagination and lazy loading, to minimize initial load times.
• Defined a unified UI design system: Built a consistent design system for both web and mobile, ensuring brand coherence and faster development cycles.
  • Collaborated with designers and the CTO to create reusable components and style guides.
• Delivered backend event-driven features: Leveraged Temporal.io to improve the reliability and scalability of complex workflows.
  • Implemented workflows for user notifications, data processing, and third-party integrations.
  • Ensured fault tolerance and retry mechanisms to gracefully handle failures.

Technologies Used

• Expo
• TypeScript
• Next.js
• EAS
• Temporal.io
• GraphQL
• TanStack Query
• MongoDB
• Github
• Datadog
• GCP

Role

• Fullstack Development
• Performance Optimization
• UI/UX Design System
• Backend Development