Senior Android Engineer (Kotlin) - Freelance (Poland)

Flix; Warszawa; On-site; PLN 96,000 - 165,000; Full time

Job summary

Flix is seeking an experienced Software Engineer for a freelance/service agreement (B2B) to own Android development across the mobile ecosystem, with a focus on performance, quality, scalability, UX and testing. You will design, build, and maintain high-quality Android apps, work with iOS and backend teams for seamless integration, and drive architecture improvements and CI/CD automation.

This Poland-based contractor role offers remote-friendly collaboration, strong emphasis on reliability,

Qualifications

• 6+ years of Android development with a proven track record of building high-quality, user-facing Android apps.
• Strong Kotlin expertise including Jetpack Compose and MVVM.
• Hands-on experience with performance optimizations, background services, memory management, and smooth user interactions.
• Experience with testing (unit, integration, UI) and commitment to testable, maintainable code.
• Ability to drive technical strategy with high standards in code quality, performance, and scalability.

Responsibilities

• Design, develop, and maintain high-quality Android applications with a focus on scalability, performance, and user experience.
• Support closely iOS, Backend, and feature teams to align on feature specifications and ensure seamless cross-platform integration.
• Drive technical improvements across the codebase, including architecture enhancements and modernization.
• Enhance app performance and UX through UI optimizations, accessibility, and battery/memory/load time improvements.
• Leverage analytics to make data-driven decisions, optimizing performance and engagement.
• Write clean, maintainable, testable code with unit, integration, and UI tests to ensure reliability.
• Contribute to CI/CD pipelines, app stability, and release processes for faster delivery.

Skills

Android development

Kotlin

Jetpack Compose

MVVM

Coroutines

UI/UX

Performance tuning

Testing

CI/CD pipelines

Firebase SDK

Tools

GitLab

Fastlane

Docker

Firebase Analytics

Job description

Flix is seeking an experienced Software Engineer for a freelance/service agreement (B2B) to own Android development across the mobile ecosystem, with a focus on performance, quality, scalability, UX and testing. You will design, build, and maintain high-quality Android apps, work with iOS and backend teams for seamless integration, and drive architecture improvements and CI/CD automation.

This Poland-based contractor role offers remote-friendly collaboration, strong emphasis on reliability,