**About The Opportunity** We are seeking a highly experienced senior Flutter engineer to join our team and help evolve a large\-scale, high\-traffic mobile application serving both sides of a U.S. marketplace: the consumer experience and the advisor experience. You will work within a mature production environment that includes real architectural complexity, legacy design decisions, active design system migrations, native platform integrations, and real\-time communication features that must perform reliably under challenging network conditions. The role is heavily focused on Flutter development, with approximately 90% of the work in Flutter/Dart and 10% involving native iOS and Android integrations. We are looking for engineers who have successfully improved and modernized existing mobile applications at scale, not just built new applications from scratch. As a senior contributor, you will play a key role in technical decision\-making, architecture evolution, mentoring, performance optimization, and delivering high\-quality user experiences across iOS and Android platforms. **Responsibilities** * Design, develop, and maintain features within a large\-scale Flutter application used by thousands of users daily * Build and optimize performance\-sensitive and real\-time mobile experiences * Diagnose and resolve performance issues including frame drops, excessive rebuilds, memory pressure, and rendering bottlenecks * Use Flutter DevTools, Xcode Instruments, and Android Studio Profilers to investigate and improve application performance * Integrate native platform capabilities and third\-party SDKs through Flutter platform channels * Develop and maintain native integrations using Swift and Kotlin * Improve the reliability of real\-time messaging and communication features, including reconnect logic, lifecycle management, and event synchronization * Implement and maintain reusable design\-system components with a strong focus on UI quality and animations * Create and maintain unit, widget, and integration tests while promoting testing best practices * Contribute to observability, monitoring, error tracking, and production issue resolution * Participate in architecture discussions, technical planning, and code reviews * Mentor other engineers and help drive technical excellence across the team * Collaborate closely with Product and Design teams to deliver accessible, responsive, and user\-centric experiences * Contribute to mobile CI/CD pipelines and release processes for iOS and Android applications **Required Qualifications** * 6\+ years of professional experience in mobile application development * At least 3 years of hands\-on experience developing and maintaining production applications with Flutter and Dart * Deep understanding of Flutter internals, including the Widget Tree, Element Tree, Render Object Tree, rendering pipeline, rebuilds, relayouts, and repaints * Strong experience optimizing Flutter application performance using Flutter DevTools and profiling tools * Hands\-on experience with state management solutions such as BLoC/Cubit, plus Riverpod or Provider * Strong knowledge of mobile architecture patterns including Clean Architecture, MVVM, and reactive programming * Experience modernizing and improving legacy or complex codebases without requiring full rewrites * Practical experience integrating native iOS and Android functionality through platform channels * Working knowledge of Swift and Kotlin for debugging and implementing native integrations * Experience consuming and integrating RESTful APIs and third\-party services * Experience with real\-time communication technologies and mobile application lifecycle management * Strong testing experience using flutter\_test, bloc\_test, Mocktail, Mockito, or similar frameworks * Experience implementing quality gates and test coverage practices within CI environments * Hands\-on experience with CI/CD platforms such as Bitrise, Fastlane, GitHub Actions, or Codemagic * Strong written and verbal communication skills with experience participating in technical decision\-making and mentoring engineers * Bachelor’s degree in Computer Science, Software Engineering, or a related field, or equivalent practical experience **Nice To Have Skills** * Experience building standalone native applications using Swift/SwiftUI or Kotlin/Jetpack Compose * Experience working on marketplace, two\-sided platform, or subscription\-based consumer products * Experience with WebSockets, streaming, or other real\-time communication architectures * Knowledge of feature flagging and experimentation platforms such as LaunchDarkly or Firebase Remote Config * Experience with mobile observability, crash monitoring, and production incident management at scale * Knowledge of accessibility standards and mobile accessibility implementation best practices * Hands\-on experience with animation and design system tooling such as Widgetbook, Material 3, Lottie, or atomic design systems * Experience