Kotlin Multiplatform Developer

Java

Kotlin Multiplatform Developer

Java
-, Warszawa +4 Locations

Link Group

Full-time
B2B
Mid
Remote
33 - 41 USDNet per hour - B2B

Job description

The Role As a key contributor to our cross-platform strategy, you will architect and refine shared business logic using Kotlin Multiplatform (KMP). Your primary focus will be on engineering high-performance networking and data layers that serve both Android and iOS ecosystems. You won't just write code—you will take full ownership of the shared codebase, ensuring it remains scalable, maintainable, and robust in production. Operating at the heart of our mobile-to-backend infrastructure, you will drive technical excellence and help shape the future of our multiplatform development standards.

Key Responsibilities

  • Cross-Platform Engineering: Design and implement core business logic and data flows using Kotlin Multiplatform to ensure seamless performance across mobile platforms.

  • API Strategy & Alignment: Partner with backend teams to define and validate API contracts. You will oversee serialization, secure authentication flows, versioning, and sophisticated error-handling strategies.

  • Quality & Testing Excellence: Build and maintain comprehensive integration and E2E testing suites specifically for KMP, ensuring the shared layer is stable and reliable.

  • Bridge Backend & Mobile: Act as a technical liaison to ensure that backend behavior perfectly aligns with mobile client requirements and user expectations.

  • CI/CD Integration: Streamline test execution within CI pipelines to achieve high coverage and deterministic results for all shared mobile components.

Requirements

  • KMP Expertise: Proven track record in building shared logic, networking layers, and data persistence using Kotlin Multiplatform.

  • Backend Savvy: Deep understanding of RESTful/API communication, including retry logic, serialization (e.g., KotlinX Serialization), and contract testing.

  • Testing Rigor: Hands-on experience with multiplatform testing frameworks to dliver high-quality, production-ready code.

  • Collaboration Skills: Ability to work effectively with backend engineers on complex schemas, auth flows, and system consistency.

  • Professional Experience: A minimum of 5 years of commercial software development experience.

Tech stack

    English

    C1

    Kotlin

    advanced

    Kotlin multiplatform

    advanced

    KotlinX Serialization

    advanced

    RESTful API

    advanced

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