Location: Medellín, Colombia (Onsite) Schedule: Monday to Friday, full-time office hours English Level: C1 (advanced proficiency required) About the Role We're looking for a Senior Mobile Developer to join our team and take ownership of our health monitoring mobile application. The app connects to a Bluetooth ring pulse oximeter and collects health data throughout the night. This is a hands-on role that requires expertise in cross-platform mobile development, Bluetooth connectivity, and background processing optimization. Key Responsibilities - Lead the development and maintenance of our Flutter and Expo mobile applications for both iOS and Android platforms - Implement and optimize Bluetooth connectivity with our ring pulse oximeter device - Address Android battery optimization challenges to ensure reliable overnight data collection - Manage the app release process for both Apple App Store and Google Play Store - Collaborate with our backend team to integrate with our Azure-hosted .NET services - Ensure the app meets health data security and privacy requirements - Provide technical leadership and work independently with minimal supervision Requirements - 7+ years of professional mobile development experience - Strong proficiency in both Flutter and Expo for cross-platform development - Deep understanding of Bluetooth Low Energy (BLE) implementation on mobile platforms - Experience with Android battery optimization techniques for background services - Proven track record of successfully publishing and maintaining apps on both Apple App Store and Google Play Store - Working knowledge of C# and .NET to collaborate effectively with our backend team, and to assist with backend work as needed - Experience with Azure services integration - Familiarity with Firebase (Authentication, Crashlytics, Analytics)• Familiarity with Sentry and PostHog - Excellence in written and verbal English communication - Strong problem-solving skills and attention to detail - Health or medical app development experience is a plus Technical Skills - Primary: Flutter/Dart, Expo/React Native, Bluetooth LE, iOS, Android - Secondary: C#, .NET, Azure, Firebase - Tools: GitHub, Sentry, PostHog, App Store Connect, Google Play Console What We Offer - Opportunity to work on innovative health technology that makes a meaningful difference - Remote-friendly work environment with flexible hours - Competitive salary based on experience - Professional development opportunities - Collaborative team culture that values independence and initiative Application Process Please submit your resume, a cover letter explaining your interest in the position, and links to relevant projects or apps you've developed. Include details about your experience with Bluetooth implementations and any health-related app development. Job Type: Full-time