adjoe

Senior Android Developer (f/m/d)

Germany Remote Senior $4.7k–$12.8k/moest.

Summary

Location: Hamburg

Employment Type: Full time

Location Type: Hybrid

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.

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.
Data-Driven Observability: Experience with Sentry, Kibana, AWS (S3, QuickSight, Athena) to monitor and analyze SDK behavior.
Build Automation & Delivery: Hands-on experience with Gradle and GitLab CI for automated testing, building, and packaging.
Plus: AdTech/programmatic advertising experience, NDK/JNI or cross-platform iOS development is valued.

Global team with relocation support to Hamburg, Germany.
Impactful projects affecting hundreds of millions of users and billions of decisions daily.
Move fast: ship solutions multiple times a day; learn from results; maintain momentum.
Direct collaboration across teams; transparent problem-solving.
Thriving, diverse team from over 40 countries; continuous learning from colleagues.
Fun environment with daily wins and energy.