Senior Kotlin Developer

🏢 Summary: Development role focused on building secure cross-platform mobile solutions using Kotlin Multiplatform Mobile aligned with Zero Trust Architecture principles. The position involves implementing strong authentication and authorization mechanisms, integrating with enterprise identity providers, and ensuring secure credential storage and runtime protection on Android and iOS. 🗂️ Requirements: Strong experience with Kotlin development, Hands-on experience with Kotlin Multiplatform Mobile (KMM), Knowledge of OAuth 2.0 and OpenID Connect, Experience implementing MFA and SSO, Experience integrating mobile apps with IAM or Identity Providers, Knowledge of secure token handling and credential storage on Android and iOS, Ability to write automated tests, Understanding of mobile security risks and mitigation techniques 📃 Skills: Kotlin, KMM, OAuth2, OpenIDConnect, MFA, SSO, IAM, Android, iOS, Keystore, Keychain, ZeroTrust 🏢 Description: Kotlin Multiplatform Developer (KMM) – Zero Trust Architecture (m/f/d) Role Overview We are looking for a Kotlin Multiplatform Developer to join a team building secure mobile solutions aligned with Zero Trust Architecture principles. The role involves developing and maintaining shared cross-platform modules using Kotlin Multiplatform Mobile (KMM) , implementing secure authentication and authorization mechanisms, and integrating with enterprise identity providers. Key Responsibilities Develop and maintain cross-platform modules using Kotlin Multiplatform Mobile (KMM) . Implement secure authentication and authorization flows such as OAuth 2.0 , OpenID Connect , MFA , and SSO . Integrate with identity providers and enforce least privilege access and continuous verification . Collaborate with security architects to embed Zero Trust principles into mobile client design. Ensure secure storage of credentials and tokens using platform-specific mechanisms (e.g., Android Keystore , iOS Keychain ). Monitor and respond to runtime security signals (e.g., device integrity checks, jailbreak/root detection). Write clean, testable, and efficient Kotlin code for both shared and platform-specific modules. Requirements Strong experience with Kotlin development. Hands-on experience with Kotlin Multiplatform Mobile (KMM) . Good understanding of security standards and protocols: OAuth 2.0 , OpenID Connect , MFA, SSO. Experience integrating mobile apps with IAM / Identity Providers . Knowledge of secure token handling and credential storage on Android/iOS. Ability to write maintainable code and automated tests. Understanding of mobile security risks and mitigation techniques. Nice to Have Experience working in environments applying Zero Trust Architecture . Familiarity with mobile device integrity solutions and anti-tampering approaches. Experience in regulated industries (banking, fintech, enterprise security).

🏢 Summary: The role focuses on architecting and maintaining shared business logic and high-performance networking/data layers using Kotlin Multiplatform for Android and iOS. You will own the shared codebase, ensure production-grade quality through robust testing, and align mobile and backend systems. The position emphasizes API strategy, CI/CD integration, and technical leadership in multiplatform development. 🗂️ Requirements: Proven experience with Kotlin Multiplatform for shared logic and networking layers, Strong knowledge of RESTful API communication and contract testing, Experience with serialization and secure authentication flows, Hands-on experience with multiplatform testing frameworks, Ability to collaborate with backend engineers on APIs and schemas, Minimum 5 years of commercial software development experience 📃 Skills: Kotlin, KotlinMultiplatform, KMP, REST, APIs, Serialization, KotlinX, Authentication, CI/CD, Testing, Android, iOS 🏢 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.

🏢 Summary: Opportunity to lead development of shared business logic and networking layers using Kotlin Multiplatform for Android and iOS platforms. The role focuses on architecting scalable, high-performance data and API layers, ensuring production stability through rigorous testing and CI integration. You will own the shared codebase and align backend and mobile systems to maintain robust, secure, and consistent cross-platform solutions. 🗂️ Requirements: Proven experience with Kotlin Multiplatform, Experience building shared business logic and networking layers, Strong knowledge of REST API communication, Experience with serialization and contract testing, Hands-on experience with multiplatform testing frameworks, Experience integrating tests into CI pipelines, Ability to collaborate with backend engineers on APIs and authentication, Minimum 5 years of commercial software development experience 📃 Skills: Kotlin, KMP, REST, APIs, Serialization, KotlinX, Android, iOS, Testing, CI, CD, Networking, Authentication 🏢 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.

🏢 Summary: Kotlin Developer role focused on building and maintaining cross-platform mobile solutions using Kotlin Multiplatform Mobile (KMM) with strong emphasis on Zero Trust Architecture and mobile application security. The position involves implementing secure authentication and authorization mechanisms and integrating identity providers in line with Zero Trust principles. 🗂️ Requirements: Experience with Kotlin Multiplatform Mobile (KMM), Experience in developing and maintaining cross-platform modules, Experience implementing OAuth 2.0, OpenID Connect, MFA or SSO, Experience integrating with identity providers, Knowledge of Zero Trust Architecture principles, Experience in secure storage of credentials and tokens, Experience in application security monitoring (device integrity, jailbreak/root detection), Ability to write clean, testable and efficient Kotlin code 📃 Skills: Kotlin, KMM, OAuth2, OpenID, MFA, SSO, ZeroTrust, Authentication, Authorization, Identity, Encryption, Security, Android, iOS 🏢 Description: Poszukujemy Kotlin Developera do pracy przy rozwiązaniach mobilnych opartych o Kotlin Multiplatform Mobile (KMM), z naciskiem na implementację zasad Zero Trust Architecture oraz bezpieczeństwo aplikacji. Zakres obowiązków Rozwój i utrzymanie modułów cross-platformowych w Kotlin Multiplatform Mobile (KMM) Implementacja bezpiecznych mechanizmów uwierzytelniania i autoryzacji (OAuth 2.0, OpenID Connect, MFA, SSO) Integracja z dostawcami tożsamości oraz egzekwowanie zasad least privilege i continuous verification Współpraca z architektami bezpieczeństwa przy wdrażaniu zasad Zero Trust w aplikacjach mobilnych Zapewnienie bezpiecznego przechowywania danych (credentials, tokeny) z wykorzystaniem mechanizmów platformowych Monitorowanie sygnałów bezpieczeństwa w czasie działania aplikacji (np. device integrity, jailbreak/root detection) Pisanie czystego, testowalnego i wydajnego kodu w Kotlinie (część wspólna i platformowa) Wymagania Doświadczenie w Kotlin Multiplatform Mobile (KMM) Doświadczenie w tworzeniu i utrzymaniu modułów cross-platformowych Doświadczenie w implementacji OAuth 2.0, OpenID Connect, MFA lub SSO Doświadczenie w integracji z dostawcami tożsamości Znajomość zasad Zero Trust Architecture Doświadczenie w bezpiecznym przechowywaniu danych (credentials, tokeny) Doświadczenie w monitorowaniu bezpieczeństwa aplikacji (np. device integrity, jailbreak/root detection) Umiejętność pisania czystego, testowalnego i wydajnego kodu w Kotlinie

🏢 Summary: Mid-Level Kotlin Android Developer role focused on building secure, scalable Android applications using modern architectures and tools in a hybrid Krakow-based model. The position involves developing Kotlin applications with Jetpack Compose, integrating network services, and implementing CI/CD pipelines while ensuring high mobile security standards. You will collaborate in distributed teams to deliver robust digital mobile solutions. 🗂️ Requirements: Minimum 4 years of Android development experience in Kotlin, Strong knowledge of Android frameworks and libraries: Retrofit, Coroutines, Room, Hands-on experience with Android Lifecycle, ViewModel, LiveData, Experience with MVP, MVVM, Clean Architecture design patterns, Practical experience with CI/CD pipelines, Knowledge of secure data storage, SSL pinning, authentication mechanisms, Understanding of modularization and dependency management, Ability to troubleshoot production issues, Fluent English (spoken and written), Legal right to work in the European Union 📃 Skills: Kotlin, Android, Jetpack, Compose, Retrofit, Coroutines, Room, Lifecycle, ViewModel, LiveData, MVP, MVVM, CleanArchitecture, Koin, Dagger, Hilt, CI/CD, SSL, Flow 🏢 Description: Empower Mobile Innovation — Drive Secure and Seamless Digital Experiences! Krakow-based opportunity with hybrid work model. As a Mid-Level Kotlin Android Developer, you will be working on developing cutting-edge Android applications that enhance customer engagement and strengthen security measures. The role focuses on delivering robust, scalable mobile solutions in a rapidly evolving digital landscape. Quick Facts: - Hybrid work model based in Krakow - Fluent English required (spoken and written) - Only candidates with an existing legal right to work in the European Union will be considered Responsibilities: - Create and develop Android applications in Kotlin, using Jetpack Compose for modern UI design - Design and implement solutions following MVP and MVVM design patterns, ensuring modularity and maintainability - Integrate applications with network services using Retrofit, ensuring secure and reliable communication - Manage dependencies using Koin, Dagger, or Hilt - Build and maintain CI/CD pipelines to streamline deployment cycles - Apply best practices in mobile security, including encrypted data storage and secure network protocols - Diagnose and resolve application issues, including production incidents - Collaborate in distributed teams, participating in code reviews, retrospectives, and knowledge sharing Requirements: - Minimum of 4 years of experience developing Android applications in Kotlin - Strong proficiency with Android frameworks and libraries: Retrofit, Coroutines, Room - Hands-on experience with Android Lifecycle, ViewModel, and LiveData - Solid understanding of modularization principles and dependency management - Practical experience establishing and maintaining CI/CD pipelines - Familiarity with MVP, MVVM, and Clean Architecture - Knowledge of mobile security best practices: secure data storage, SSL pinning, authentication mechanisms - Ability to troubleshoot and resolve complex technical issues, including in production environments - Willingness to work in distributed teams and actively participate in code reviews Nice to Have: - Experience with Flow for asynchronous programming - Certifications related to Android development or cybersecurity

🏢 Summary: Mid-Level Kotlin Android Developer role focused on building secure, scalable mobile applications using modern Android technologies and architecture patterns. The position involves developing Kotlin-based apps with Jetpack Compose, integrating network services, and maintaining CI/CD pipelines in a hybrid Kraków-based setup. The role emphasizes high-quality, user-centric solutions within distributed teams. 🗂️ Requirements: Minimum 4 years of Android development experience with Kotlin, Strong knowledge of Android framework, Experience with Retrofit, Coroutines, and Room, Experience with MVP, MVVM, and Clean Architecture, Practical experience with CI/CD processes, Knowledge of mobile security practices including SSL pinning and encrypted data storage, Ability to troubleshoot and resolve technical issues, Fluent English (spoken and written), Legal right to work in the European Union 📃 Skills: Kotlin, Android, JetpackCompose, Retrofit, Coroutines, Room, ViewModel, LiveData, Koin, Dagger, Hilt, MVP, MVVM, CleanArchitecture, CICD, SSL, Encryption, Authentication, Flow 🏢 Description: Ignite the future of mobile innovation — shape seamless user experiences with Kotlin! Kraków-based opportunity with hybrid work model As a Mid-Level Kotlin Android Developer , you will be working for our client, a leader in digital transformation within the mobile platform industry. You will contribute to the development of cutting-edge mobile applications that enhance customer engagement and drive innovation in a data-driven world. Join a team committed to building secure, scalable, and user-centric digital solutions for today’s dynamic market. Your main responsibilities: Develop and enhance mobile applications in Kotlin, utilizing Jetpack Compose for modern UI design. Design and implement solutions based on MVP and MVVM architecture patterns. Integrate apps with network services using Retrofit and manage application state with ViewModel and LiveData. Manage dependencies effectively with tools such as Koin, Dagger, or Hilt. Create and maintain robust CI/CD pipelines to streamline deployment processes. Ensure application security by implementing secure data storage and network communication protocols. Participate in code reviews, retrospectives, and collaboration within distributed teams. Troubleshoot and resolve production incidents, ensuring high-quality user experiences. You're ideal for this role if you have: Minimum 4 years of experience in Android application development with Kotlin. Very good knowledge of Android framework and libraries such as Retrofit, Coroutines, Room. Strong understanding of application lifecycle, modularity principles, and dependency management. Practical experience with CI/CD processes. Familiarity with design patterns MVP, MVVM, and Clean Architecture. Knowledge of mobile security best practices including SSL pinning, encrypted data storage, and user authentication. Ability to diagnose and troubleshoot technical issues efficiently. Excellent communication skills in English (fluent level). Willingness to work in distributed teams and participate actively in knowledge sharing. It is a strong plus if you have: Certifications related to Android development or security. Experience with asynchronous programming models like Flow. Language required for the role: Excellent command of English, fluent in both spoken and written communication. Eligibility to work in this role: Only candidates with an existing legal right to work in the European Union will be considered for this role. #MAKEYourCareerBETTER Interested? Apply now and include your CV (preferably in English) along with a statement confirming your consent to the processing and storage of your personal data.

🏢 Summary: Senior Mobile Engineer role focused on designing and delivering high-quality, scalable mobile applications for both iOS and Android in an international project. The position involves contributing to architecture decisions, ensuring performance and security, and maintaining code quality through best practices and testing. 🗂️ Requirements: 7+ years of mobile development experience, Strong experience with iOS development using Swift, Strong experience with Android development using Kotlin, Solid understanding of MVVM or Clean Architecture, Experience integrating RESTful APIs, Knowledge of mobile performance, scalability, and security best practices, Experience working with Agile methodologies (Scrum or Kanban) 📃 Skills: Swift, Kotlin, iOS, Android, MVVM, CleanArchitecture, REST, Performance, Scalability, Security, Agile, Scrum, Kanban 🏢 Description: We are looking for a Senior Mobile Engineer with strong experience in both iOS (Swift) and Android (Kotlin) to join an international project focused on building high-quality mobile applications. Main Responsibilities: Design, develop, and maintain mobile applications for both iOS and Android platforms Contribute to the architecture and technical decisions of mobile solutions Build scalable, high-performance, and user-focused applications Collaborate closely with Product Managers, Designers, and other Engineers Ensure code quality through best practices, code reviews, and testing Troubleshoot, debug, and optimize application performance Key Requirements: 7+ years of experience in mobile development Strong hands-on experience with: iOS (Swift) Android (Kotlin) Solid understanding of mobile architectures (e.g., MVVM, Clean Architecture) Experience integrating RESTful APIs Knowledge of mobile performance, scalability, and security best practices Experience with Agile methodologies (Scrum/Kanban) Strong problem-solving skills and attention to detail Good communication skills in English Nice to Have: Experience with cross-platform solutions (e.g., Kotlin Multiplatform, Flutter, React Native) Familiarity with CI/CD pipelines for mobile applications Experience with automated testing (unit/UI) Knowledge of mobile app distribution processes (App Store / Google Play)

🏢 Summary: Senior Android Engineer role focused on building and maintaining a large-scale mobile product using Kotlin and Jetpack Compose, with strong ownership of architecture, scalability, and code quality. The position involves working within a mature Android ecosystem, ensuring high performance and robust engineering standards. Candidates are expected to contribute autonomously to mobile architecture and delivery processes. 🗂️ Requirements: Strong Kotlin proficiency, Experience with Jetpack Compose, Deep knowledge of Android SDK, Understanding of OOP principles, Knowledge of algorithms, Knowledge of data structures, Experience with Gradle build systems, Experience with CI pipelines, Ability to work autonomously, Strong problem-solving skills 📃 Skills: Kotlin, Compose, Android, AndroidSDK, OOP, Algorithms, DataStructures, Gradle, CI, KMM, TDD, Copilot, PairProgramming, ModularArchitecture 🏢 Description: Senior Android Engineer (Kotlin / Compose) We are looking for an experienced Android Engineer who thrives in large-scale product environments and takes ownership of mobile architecture and delivery quality. You’ll work on a mature mobile ecosystem where scalability, performance, and engineering standards matter. What We’re Looking For Strong proficiency in Kotlin and modern Jetpack Compose for UI development Deep understanding of the Android SDK and native mobile development principles Solid knowledge of Object-Oriented Programming , algorithms, and data structures Experience working with Gradle-based build systems and CI pipelines Ability to work with a high level of autonomy and strong problem-solving mindset Additionally Valued Experience with modular architecture (e.g., Kotlin Multiplatform Mobile – KMM) Experience working within large and evolving codebases Practical exposure to Test-Driven Development (TDD) and Pair Programming Experience leveraging AI-assisted development tools (e.g., Copilot)

🏢 Summary: Development of a native Android application in the Language Intelligence domain, leveraging AI and NLP to process and analyze large-scale text data. The role focuses on building scalable, high-quality UI solutions with Kotlin and Jetpack Compose, and integrating AI-driven features. The position also involves contributing to architecture, CI/CD processes, and overall application performance and stability. 🗂️ Requirements: Strong knowledge of Kotlin, Experience with Jetpack Compose, Solid experience with Android SDK, Experience in native Android development, Understanding of OOP principles, Knowledge of algorithms and data structures, Experience with Gradle build processes, Experience with CI systems 📃 Skills: Kotlin, JetpackCompose, Android, AndroidSDK, Gradle, CI, OOP, Algorithms, DataStructures, NLP, AI 🏢 Description: The project is developed in the Language Intelligence area. It uses AI and NLP technologies to analyze and process large-scale text data. The solution supports key features of a digital platform, such as search, content quality, and process automation. Our expectations: Strong knowledge of Kotlin and Jetpack Compose for UI development. Solid experience with Android SDK and native Android development. Good understanding of Object-Oriented Programming (OOP), algorithms, and data structures. Experience with Gradle build processes. Experience working with Continuous Integration (CI) systems. High level of independence, good work organization, and strong problem-solving skills. Native level of Polish and English at B2 level. Nice to have: Experience with modular architecture (e.g. Kotlin Multiplatform). Experience working with large codebases. Practical knowledge of Test-Driven Development (TDD) and Pair Programming. Experience in AI-supported software development, e.g. using tools like GitHub Copilot. Main responsibilities: Develop and maintain native Android applications using Kotlin and Jetpack Compose. Design and implement user-friendly and scalable UI solutions. Work with AI and NLP-based features for text analysis and processing. Collaborate with product managers, backend developers, and data teams. Ensure high code quality, performance, and application stability. Participate in code reviews and knowledge sharing within the team. Contribute to architecture decisions and modular code design. Support and improve CI/CD pipelines and build processes. Identify, analyze, and solve technical problems independently. Write clean, maintainable, and testable code.

🏢 Summary: Opportunity to lead the development of a cross-platform mobile app built with Kotlin Multiplatform for Android and iOS, taking full ownership of architecture, shared components, and UI/UX patterns. The role involves close collaboration with backend and design teams to deliver scalable, high-performance mobile experiences. You will shape the technical foundations of the product as part of the founding engineering team. 🗂️ Requirements: 4+ years of Android development experience, Strong proficiency in Kotlin, Production experience with Jetpack Compose, Hands-on experience with Kotlin Multiplatform, Experience with mobile architecture patterns (MVI or MVVM), Experience designing mobile app architecture, Experience integrating mobile apps with backend APIs 📃 Skills: Kotlin, Android, iOS, Jetpack, Compose, KotlinMultiplatform, MVI, MVVM, REST, API 🏢 Description: About the company We are a new AI startup, recently funded, creating the next generation of digital experiences for collectibles and trading cards, like game cards, sports cards, and more. The company was started by two experienced entrepreneurs who have built and grown successful companies before, including a gaming unicorn. We are now forming our founding engineering team. This team will help shape the product, company culture, and engineering standards. We use modern tools, LLM-assisted development, automation, and fast iteration. We are looking for smart and motivated engineers who enjoy working with less guidance, more ownership, and some uncertainty. Most of our work happens on-site. About the role You will take full responsibility for our mobile app, built with Kotlin Multiplatform for both Android and iOS. You will help design the app’s architecture, set UI/UX patterns, and work closely with backend and design teams. What you’ll do Build the main app in Kotlin Multiplatform for Android and iOS Set up clean architecture patterns and shared components across platforms Work with backend to create mobile-friendly APIs and data structures Collaborate with design to make smooth, polished, and fast user experiences Who you are 4+ years of Android development experience, strong in Kotlin Experience with Jetpack Compose in production or serious side projects Experience with Kotlin Multiplatform Comfortable with client architecture patterns (MVI, MVVM, etc.) Take ownership and have a good product sense Enjoy creating UI experiences with care, speed, and quality What it’s like to work here High ownership, low bureaucracy Chance to shape company culture and the codebase from the start Work directly with founders and product team Competitive salary and meaningful equity Fast-paced environment, no silos, no drama