Senior Android Developer (f/m/d)
Location: Hamburg
Employment Type: Full time
Location Type: Hybrid
What you’ll do
- Own the core development and optimization of the adjoe Ads SDK (Kotlin & Android Internals), running inside hundreds of publisher apps, ensuring zero tolerance for instability across millions of devices.
- Collaborate with backend teams to design APIs and capture behavioral signals powering 50 billion daily ML predictions; design APIs with backward-compatible changes for thousands of external integrators; work with high-performance networking protocols (gRPC, Protobuf, Wire, OkHTTP).
- Design for minimal footprint to optimize battery and memory usage, ensuring native and fast ad impressions inside third-party apps.
- Monitor, debug, and maintain SDK reliability at scale; use observability and data tools (Sentry, Kibana, AWS: S3, QuickSight, Athena) to turn data into engineering decisions.
- Maintain and improve CI/CD pipelines (Gradle, GitLab CI) to automate testing, building, and packaging of mobile libraries.
- Plus – contribute experience in ad-tech/programmatic advertising (IAB specifications), NDK/JNI (C/C++ interop on Android), or cross-platform iOS development to support the ecosystem.
Who we are looking for
- Kotlin & Android Internals Expertise: 5+ years of Android experience (or 3+ years in SDK/library development) with deep understanding of Android lifecycles, ProGuard/R8, and multithreading.
- High-Performance Network Design: Strong API design background with backward compatibility for external integrators; experience with gRPC, Protobuf, Wire, OkHTTP.
- Resource-Constrained Optimization: Ability to design for minimal footprint, optimize battery and memory usage for code running inside other apps/devices.
