At least 2-3 years of experience developing and publishing mobile applications on iOS and/or Android platforms App Store publishing experience - familiarity with Apple App Store and Google Play Store submission, review processes, and ongoing maintenance Communication/chat feature implementation - experience building real-time messaging, notifications, and team collaboration features Performance optimization - experience handling high-engagement traffic and ensuring app stability under load Security best practices - implementing secure authentication, data encryption, and privacy compliance for internal/external user access Testing and debugging - proficiency in mobile testing frameworks, crash analytics, and iterative improvement based on feedback