Senior Flutter Developer – Global Market Research Organisation – 12 month contractOverviewI am currently recruiting for a Senior Flutter Developer to join my client who are a Global Market Research Organisation’s. The organisation operates a large-scale passive measurement platform across European and APAC markets, combining technologies such as audio content recognition (ACR), location tracking, and survey research to measure real-world media exposure and advertising effectiveness for enterprise clients.The company’s consumer-facing platform is expanding internationally across both Europe and Asia. The mobile platform runs on both iOS and Android and serves real users across multiple markets, meaning engineering decisions have immediate impact at scale.Role ResponsibilitiesLead and contribute to large-scale refactoring of an existing Flutter codebase, improving architecture, maintainability, and performance.Develop and maintain mobile applications built with Flutter and Dart that run in production across multiple international markets.Work closely with backend teams to ensure efficient end-to-end API integrations, optimizing performance and reliability between mobile clients and backend services.Identify architectural bottlenecks within the mobile platform and propose and implement technical improvements.Implement and maintain robust CI/CD pipelines for mobile builds, testing, and deployments.Diagnose and resolve performance issues such as memory leaks, rendering performance issues, excessive widget rebuilds, and battery consumption problems using Flutter DevTools and platform-specific profiling tools.Essential Skills and ExperienceStrong professional experience with Dart and the Flutter framework, delivering production-grade mobile applications used by a substantial user base.Proven experience leading or executing large-scale refactoring projects within Flutter codebases.Deep understanding of mobile architecture and state management patterns such as BLoC, Riverpod, or equivalent frameworks.Strong experience integrating RESTful APIs and GraphQL, including optimization of network-layer performance through caching strategies, request batching, error handling, and retry logic.Hands-on experience building and maintaining mobile CI/CD pipelines (e.g., Fastlane, GitHub Actions, Bitrise), including automated testing, build distribution, and app store deployment workflows.Demonstrated ability to identify and resolve mobile performance bottlenecks, including memory leaks, UI rendering issues, and inefficient widget rebuilds.Experience implementing mobile platform capabilities such as push notifications, background processing, secure authentication flows, local storage, and offline-first functionality.Ability to quickly understand and work within an existing production codebase with minimal onboarding.Desirable Skills and ExperienceUnderstanding of backend architecture concepts and how API design impacts mobile performance and user experience.Experience with data synchronization strategies, offline data handling, and conflict resolution mechanisms.Familiarity with cloud infrastructure environments such as AWS, GCP, or Azure, and how mobile clients interact with backend services at scale.PackageInitial 12 month contract (high possibility of extension)Flexible salary dependent on level of experienceExcellent benefitsHybrid (3x week in Groningen)