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April 8, 2026

Senior Mobile Engineer (Flutter + iOS)

Senior • Remote

6,000 - 7,000 USD

Krakow, Poland

#4966

Our client is a leading, fully regulated US-based digital asset trading platform. They provide secure, low-latency access to cryptocurrency markets, acting as a bridge between traditional finance and the Web3 ecosystem.

The Senior Software Engineer will play a pivotal role in transitioning the core mobile platform from native environments to a unified Flutter/Dart codebase. You will maintain the stability of the existing production iOS app while architecting and developing robust, scalable cross-platform features, ensuring a seamless migration process.

Key Responsibilities:

  • Maintain, enhance, and support our production native iOS application written in Swift.

  • Collaborate on the design and development of a new Flutter/Dart codebase, ensuring performance and scalability.

  • Build cross-platform mobile features in partnership with Android engineers, backend developers, and product teams.

  • Contribute to shared tooling, CI/CD pipelines, and deployment workflows.

  • Uphold high engineering standards and best practices throughout the hybrid mobile migration.

  • Troubleshoot and resolve integration, compatibility, and performance issues in both native and cross-platform stacks.

  • Provide mentorship to fellow mobile engineers, especially on iOS and native integrations.

Required Qualifications:

  • 5+ years of professional mobile development experience, including 3+ years of iOS development using Swift.

  • At least 1-2 years of hands-on experience with Flutter/Dart or demonstrated ability to adopt new cross-platform technologies.

  • Experience supporting production iOS apps through multiple OS cycles.

  • Understanding of platform interoperability, including Flutter platform channels and native SDK integration.

  • Proficiency in CI/CD and release workflows: Fastlane, App Store Connect, TestFlight.

  • Familiarity with performance monitoring tools like Xcode Instruments, Flutter DevTools, and Firebase.

  • Strong architectural judgment, especially in platform migrations or codebase rewrites.

Preferred Qualifications:

  • Exposure to Android development (Kotlin) and full cross-platform transitions.