Mobile Full Stack Developer
We are looking for an experienced Mobile Full Stack Developer who can build both mobile applications and the backend services that power them.
Flutter and Dart will be your primary mobile technologies, complemented by Swift and Kotlin for native iOS and Android functionality. Backend development is an essential part of this role. You will own features end to end — from mobile interfaces and platform integrations to server-side logic, databases, and production releases.
Who are we?
We are Out Of The Box Systems: a Ukrainian team specializing in Rust Development, AI Engineering, Computer Graphics, Automation, and Custom Software Development.
We value ownership, accountability, continuous learning, and practical problem-solving. Our team works remotely with clients from the USA, Canada, Europe, and other international markets.
Workload
- Full-time remote collaboration
- Long-term projects
- Direct communication with clients and engineering teams
Responsibilities
- Build and maintain iOS and Android applications using Flutter and Dart
- Develop native functionality using Swift and Kotlin, including SDK integrations and Flutter platform channels
- Design maintainable application architecture and adaptive interfaces for smartphones and tablets
- Develop and maintain backend services, APIs, database integrations, and authentication; integrate AI-powered features
- Implement local storage, offline functionality, data synchronization, push notifications, and deep links
- Optimize performance, stability, and memory usage
- Collaborate with the team through code reviews, automated testing, and technical discussions
- Support mobile and backend deployment, CI/CD, App Store and Google Play releases, and ongoing maintenance
Required Skills
- Strong commercial mobile development experience, including production applications built with Flutter and Dart
- Solid understanding of Flutter layouts, navigation, application lifecycle, and state management using BLoC, Riverpod, or similar tools
- Practical experience with Swift and Kotlin: ability to read, debug, and modify native code on both platforms
- Familiarity with UIKit or SwiftUI and Android Views or Jetpack Compose, including native SDK integration
- Experience integrating REST APIs and implementing local databases and offline data handling
- Hands-on backend development experience with at least one technology stack, including building APIs, implementing server-side logic, working with databases, and managing authentication and authorization
- Practical experience integrating AI services or APIs
- Understanding of software architecture, asynchronous programming, dependency injection, and memory management
- Experience with Git, automated testing, debugging, performance profiling, and mobile release workflows
- Upper-Intermediate English (B2) or higher
Preferred Skills
- Advanced native development experience with iOS or Android
- Experience with Firebase, Supabase, cloud infrastructure, or Docker
- Experience with secure storage, in-app purchases, subscriptions, analytics, or crash reporting
- Experience with Rust or C++, native library integration, or performance-critical mobile applications
What You Get
- Long-term collaboration on challenging international projects
- Competitive compensation based on your skills and experience
- Remote work with an experienced engineering team
- Transparent communication and a supportive team culture
- Professional growth through mentorship, feedback, and hands-on experience
- A 2-year B2B contract reflecting our commitment to long-term collaboration