Senior Android Engineer - Kotlin, Scalable Apps (Freelance)

Flix; Województwo mazowieckie; Remote; PLN 165,000 - 331,000; Part time

Job summary

Flix is seeking an experienced Software Engineer on a freelance/B2B basis to shape high-quality Android apps for the Flix passenger journey. You will design, develop, and maintain scalable apps with a focus on performance, UX, and testing, while coordinating with iOS, backend, and feature teams for seamless integration.

The role emphasizes architecture improvements, codebase modernization, and data-driven decisions using analytics.

Qualifications

• 6+ years of Android development with a strong track record of user-facing apps.
• Expertise in Kotlin, Jetpack Compose, MVVM, and coroutines.
• Hands-on with performance optimizations, memory management and smooth UI.
• Experience writing tests (unit, integration, UI) and testable code.
• Familiarity with CI/CD pipelines and automated deployment (GitLab, Fastlane).
• Experience with Firebase Analytics, Remote Config and Crashlytics.

Responsibilities

• Design, develop, and maintain scalable Android apps with focus on UX and performance.
• Collaborate with iOS, backend, and feature teams for cross‑platform integration.
• Drive architecture improvements and codebase modernization.
• Improve app performance, accessibility, battery/memory usage, and load times.
• Leverage analytics to optimize engagement and app health.
• Contribute to CI/CD pipelines, app stability, and faster releases.
• Document APIs, architecture decisions, and code comments for knowledge sharing.

Skills

Android

Kotlin

Jetpack Compose

MVVM

Coroutines

Performance tuning

UI testing

CI/CD

Firebase Analytics

Crashlytics

Tools

GitLab

Fastlane

Docker

Firebase

Job description

Flix is seeking an experienced Software Engineer on a freelance/B2B basis to shape high-quality Android apps for the Flix passenger journey. You will design, develop, and maintain scalable apps with a focus on performance, UX, and testing, while coordinating with iOS, backend, and feature teams for seamless integration.

The role emphasizes architecture improvements, codebase modernization, and data-driven decisions using analytics.