Senior Android SDK Developer

Job Description Velotio Technologies is a product engineering company working with innovative startups and enterprises. We have provided full-stack product development for 110+ startups across the globe, building products in the cloud-native, data engineering, B2B SaaS, IoT & Machine Learning space. Our team of 400+ elite software engineers solves hard technical problems while transforming customer ideas into successful products. 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 Benefits Our Culture: - We have an autonomous and empowered work culture encouraging individuals to take ownership and grow quickly - Flat hierarchy with fast decision making and a startup-oriented get things done culture - A strong, fun & positive environment with regular celebrations of our success. We pride ourselves in creating an inclusive, diverse & authentic environment We want to hire smart, curious and ambitious folks so please reach out even if you do not have all of the requisite experience. We are looking for engineers with the potential to grow At Velotio, we embrace diversity. Inclusion is a priority for us, and we are eager to foster an environment where everyone feels valued. We welcome applications regardless of ethnicity or cultural background, age, gender, nationality, religion, disability or sexual orientation.