We are seeking a Senior Android Developer with expertise in building Android software development kits (SDKs) to join our team. In this role, you will lead the end-to-end development of Android SDKs that will be integrated by other developers into their applications. The ideal candidate is an expert in Kotlin and Java, has a strong grasp of Android architecture and design patterns, and has a proven track record of publishing and maintaining Android libraries. You will drive the SDK's design, implementation, documentation, and long-term maintenance, ensuring high performance, reliability, and backward compatibility. This is a senior-level technical role that requires hands-on development, strategic thinking, and the ability to collaborate effectively in a hybrid work environment. Requirements Design & Build: Craft modular, high-performance Android SDKs in Kotlin (and supportive Java) that are easy to integrate and extend SDK Lifecycle Ownership: Own the full SDK development lifecycle including planning, development, testing, and release. Manage versioning (semantic versioning) and long-term maintenance for continuous improvement of the SDK. Release Management: Publish artifacts to Maven Central / JitPack, manage semantic versioning, changelogs, and ensure backward compatibility Performance & Reliability: Profile, benchmark, and optimize for low memory, battery, and network usage across a wide device matrix Security & Compliance: Implement encryption, token handling, and privacy-first data practices - crucial for payment and analytics use cases Documentation & Samples: Produce clear guides, Javadoc/KDoc, and sample apps so external teams can get started in minutes Collaboration: Partner with product, backend, and QA to define features, automate CI/CD (GitHub Actions/Bitrise), and drive code reviews What you will bring: 5+ years of Android development with deep Kotlin expertise and solid Java fundamentals Demonstrated success shipping at least one widely adopted Android SDK or open-source library Hands-on with Gradle plugin configuration, dependency management, ProGuard/R8, and publishing pipelines. Strong debugging skills using Android Studio Profiler, Logcat, and crash-reporting tools (e.g., Firebase Crashlytics, Sentry) Excellent written communication; able to translate complex concepts into concise developer documentation Core Android Development Kotlin 1.9 / 2.x & Java 11+: expert-level proficiency Android API 23 - 34: deep platform knowledge, multi-APK/AAB experience Jetpack Compose 1.6+ & ViewSystem XML Gradle 8.x (KTS), modular multi-module projects, dependency management Security & Cryptography AES-256, RSA-2048, SHA-256, Keystore hardware-backed keys PCI DSS, OWASP M-STG best practices, secure memory handling SafetyNet / Play Integrity, certificate pinning, TLS 1.3 Network & API Development Retrofit 2, OkHttp 5, Kotlinx Serialization / Moshi Coroutines & Flow, exponential backoff, connectivity awareness Architecture & Patterns MVVM, Clean Architecture, Repository, DI (Hilt/Dagger), Builder/Factory Modular Gradle projects, feature flags, dynamic feature delivery Testing & CI/CD Unit (JUnit 5), Instrumentation (Espresso), Robolectric, MockK Code-coverage enforcement, static analysis (Detekt, Lint) Automated pipelines with GitHub Actions, Bitrise, or Jenkins Payment Domain Knowledge PAN/PCI tokenization, CVV-less flows, 3-D Secure 2.x EMVCo specs, gateway APIs, recurring billing, chargeback flows Bonus Points if you have........ Prior experience in payment processing (tokenization, 3-D Secure) or analytics/event-tracking SDKs Knowledge of CI/CD for mobile (Fastlane, Bitrise, or GitHub Actions) and automated testing of libraries Contributions to open-source Android projects or active presence in the dev community

About Velotio Technologies

Velotio Technologies is a leading product engineering and digital solutions company working with innovative startups and enterprises across the globe. With a team of 325+ engineers, we specialize in Full-Stack development, Web & Mobile App Development, Cloud & DevOps, Data Engineering, Media Product Development, AI/ML, Experience Design (UI/UX), and Quality Assurance. We also help enterprises accelerate their digital transformation roadmap for a competitive edge with our strategy & consulting services. Since our inception in 2016, we have worked with over 110 global customers, including NASDAQ-listed enterprises, unicorn startups, YCombinator and Sequoia-funded companies, and cutting-edge product companies. We are recognized as a 'Top software development company' by Clutch and GoodFirms. We have been certified as a Great Place to Work® for two consecutive years and named one of India's Best Workplaces for Women. And we at Velotio take great pride in our transparent work atmosphere, meaningful peer relationships, and the 'Velotio tech geek community.' You can read more about our work culture at Life@Velotio- https://www.velotio.com/life-at-velotio.