SDET (Flutter)

Warsaw, Mazowieckie (Hybrid)

X-FLOW is a mobile game development company established in 2018. We gained recognition after the release of Happy Color, the most popular digital coloring book and one of the most successful ad-driven mobile apps in the world. We take pride in our diverse and talented team and partners, spread across the UK, Cyprus, the Netherlands, and other regions worldwide.

We are looking for a proactive Senior SDET with deep expertise in Flutter app testing for our flagship project, Happy Color.

Key Responsibilities:

• Design, scale, and maintain a comprehensive test automation strategy for our Flutter application across all levels: unit, widget, integration, golden/visual regression, and API/contract testing.

• Build and support test automation infrastructure in Dart and Flutter using flutter_test, integration_test, and other relevant tools.

• Architect the test automation project from scratch, establishing engineering standards, design patterns, and best practices.

• Drive effective test coverage, prioritizing critical user journeys, core business logic, application stability, and API reliability.

• Implement code coverage tracking for unit and widget tests, define minimum coverage thresholds, and set up automated quality gates for Merge Requests (MRs).

• Enforce strict quality criteria, ensuring MRs are automatically blocked if coverage drops, required tests fail, or quality standards are violated.

• Integrate test execution into CI/CD pipelines, including unit/widget/golden tests on MRs and integration/E2E test runs on emulators, simulators, and real devices.

• Contribute to mobile app observability: define quality metrics, monitor crash rate, ANR, app launch time, screen performance, and scenario stability; validate logging, analytics events, and error handling; help integrate performance monitoring and crash reporting tools.

• Conduct thorough code reviews for test suites (unit, widget, integration, golden, and E2E).

• Participate in product Flutter code reviews to ensure testability, stability, and adherence to quality engineering practices.

• Help define and evolve the Android/iOS device matrix, taking into account OS versions, screen resolutions, hardware performance, and platform-specific behavior.
  

Requirements:

• 5+ years of experience in mobile test automation.

• 2+ years of hands-on experience with Flutter and Dart.

• Strong proficiency in writing unit, widget, integration, golden, and API/contract tests.

• Deep understanding of Flutter test frameworks (flutter_test, integration_test) and test architecture patterns.

• Experience integrating test automation into CI/CD pipelines and establishing automated quality gates for MRs.

• Solid understanding of Flutter interactions with native platforms (Android and iOS).

• Familiarity with mobile app performance profiling, observability, and crash reporting tools (monitoring ANRs, launch times, crash rates).

• Russian — C1 or higher, English — B1+.
  

What We Offer:

• Competitive salary and benefits package.

• Opportunity to work with a talented and passionate team in a creative and dynamic environment.

• Flexible working hours and remote/office work options.

• Career growth and professional development opportunities.

• A fun and inclusive company culture that celebrates diversity and creativity.