Lead Cross-Platform Mobile App Developer (Flutter/Firebase) - iOS & Android

We are seeking a Lead Cross-Platform Mobile App Developer to build, launch, and maintain Perfecti on iOS and Android. You will own the application lifecycle-from architecture and development through testing, store deployment, monetization, and ongoing optimization. The app will use Flutter, Firebase, and a freemium subscription model., * Build and maintain one cross-platform application using Flutter and Dart.

• Design scalable architecture for iOS and Android.
• Integrate Firebase Authentication, Cloud Firestore, Cloud Functions, Cloud Storage, Analytics, Crashlytics, Cloud Messaging, and App Check.
• Create secure Firestore data models, access rules, indexes, and backup strategies.
• Implement freemium features, subscriptions, and in-app purchases using Apple StoreKit, Google Play Billing, or RevenueCat.
• Integrate REST APIs, SDKs, and third-party services.
• Translate product and UI/UX requirements into responsive, accessible features.
• Write clean, documented, maintainable code using established architecture and state-management patterns.
• Build automated unit, widget, integration, and end-to-end tests.
• Configure CI/CD, development environments, release builds, and versioning.
• Manage TestFlight, App Store Connect, Google Play Console, store submissions, and review issues.
• Monitor crashes, performance, analytics, subscription events, and operating costs.
• Apply privacy, security, and data-protection best practices.
• Maintain the codebase in GitHub and provide clear project documentation.
• Communicate progress, risks, estimates, and technical recommendations., * Have you independently taken a Flutter application from requirements through production release on both iOS and Android? Describe the project, your role, timeline, and the most difficult issue you resolved.
• Store Deployment: Describe your direct experience with App Store Connect, TestFlight, Google Play Console, signing certificates, provisioning profiles, release tracks, privacy disclosures, and store-review rejections. Provide an example of a submission problem you personally resolved.
• Flutter Architecture: How would you structure a new production Flutter application for long-term scalability? Identify the architecture, state-management approach, testing strategy, and folder structure you would use and explain why.
• Availability: What is your hourly rate, weekly availability, time zone, and earliest start date? Are you personally performing the work, or will any portion be assigned to another developer?
• Firebase and Firestore: Describe a Flutter application in which you used Firebase Authentication, Cloud Firestore, Cloud Functions, Cloud Messaging, Analytics, and Crashlytics. How did you structure the data and control access?
• Freemium Subscriptions: Describe your experience implementing freemium access, free trials, and recurring subscriptions on iOS and Android. Which tools did you use, and how did you handle receipt validation, entitlement synchronization, purchase restoration, cancellations, and subscription expiration?

• Extensive production experience with Flutter and Dart.
• Demonstrated success launching and maintaining Flutter applications on both the Apple App Store and Google Play.
• Strong experience with Firebase Authentication, Cloud Firestore, Cloud Functions, Cloud Storage, Cloud Messaging, Analytics, Crashlytics, Remote Config, and App Check.
• Expertise in Firestore security rules, NoSQL data modeling, offline synchronization, indexes, and query optimization.
• Experience implementing subscriptions, free trials, entitlement management, receipt validation, and purchase restoration.
• Knowledge of Apple and Google billing policies and store-review requirements.
• Proficiency with REST APIs, JSON, OAuth, webhooks, and third-party SDK integration.
• Experience with Flutter state management such as Riverpod, BLoC, or Provider.
• Understanding of clean architecture, dependency injection, responsive design, accessibility, and platform-specific behavior.
• Familiarity with Swift and Kotlin for native integrations and troubleshooting.
• Strong mobile security knowledge, including secure credential storage, API protection, authentication, authorization, and abuse prevention.
• Experience with GitHub, pull requests, code reviews, automated testing, and CI/CD tools such as GitHub Actions or Codemagic.
• Ability to test and debug across multiple iPhone, iPad, and Android devices and operating-system versions.
• Understanding of privacy disclosures, account deletion, data retention, consent, and App Store privacy requirements.
• Strong written communication, documentation, estimation, and independent problem-solving skills.

Candidates should provide links to live iOS and Android applications they personally helped build, explain their specific contributions, and describe their experience with Firebase and mobile subscriptions.

3.63.6 out of 5 stars Remote $30 an hour - Contract