Kotlin/Java Android Developer with German

B2B | Remote (EU-based) | Full-time | Long-term project | Start: June 2025

We are looking for an experienced Android Native Developer to join our international team working on secure digital identity and authorization systems for a German public sector project. You will help develop modern, secure, and user-friendly Android applications that handle sensitive user data and implement advanced authentication protocols.

This is a long-term engagement in a regulated environment with a strong focus on privacy, cryptography, and compliance. You’ll work as part of a stable, cross-functional team including backend developers, UX/UI designers, QA, and DevSecOps engineers.

Project overview

• Development of secure mobile applications for digital identity management

• Implementation of cryptographic protocols and secure communication features

• Collaboration with a multidisciplinary international team

• Long-term public sector project (2–3 years, with a strong likelihood of extension)

• Remote work from within the EU, with occasional on-site visits in Germany

• Planned start date: June 2025

Responsibilities

• Design and development of native Android applications using Kotlin or Java

• Implementation of authentication and authorization functionality

• Development of secure storage and communication modules (e.g. BLE, NFC)

• Integration of biometric authentication and secure hardware features

• Close collaboration with UX/UI teams to deliver accessible, intuitive interfaces

• Implementation of testing processes including unit, UI, and integration testing

• Participation in code reviews and application of security best practices

• Contribution to the continuous improvement of the development process

Requirements

• Minimum 3 years of experience in native Android development using Kotlin or Java

• Proficiency in Android Studio, Gradle, and ADB

• At least 12 months of experience with Material Design and Jetpack Compose

• Solid knowledge of native Android APIs, including:

• TEE/StrongBox for secure key storage

• BLE (Bluetooth Low Energy)

• NFC communication

• OMAPI (Open Mobile API)

• BiometricPrompt

• Experience with testing tools such as Espresso and Appium

• Understanding of cryptographic techniques and secure communication standards

• Familiarity with Git-based development workflows

• Proficiency in both German and English (minimum B2 level)

Nice to have

• Experience with UI design tools such as Figma

• Familiarity with identity protocols: OAuth2, OpenID Connect, SAML

• Knowledge of FIDO standards and verifiable credentials

• Experience with JWT and digital identity frameworks

• Understanding of eIDAS regulations and compliance requirements

• Previous experience publishing apps to the Google Play Store

🗂️ Note: We’re currently building a talent pool for upcoming projects. If you’d like to be considered for future opportunities at Kyotu, send us your CV — we’ll reach out when a matching project becomes available.